kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-15 19:56:03 +00:00
Code Issues Releases Packages Activity
linux/drivers/cpufreq/cpufreq_conservative.c

345 lines
8.8 KiB
Raw Normal View History

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 10:11:33 +02:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] conservative: amend author's email address Amend author's email address. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-13 19:01:01 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
cpufreq: governor: Relocate definitions of tuners structures Move the definitions of struct od_dbs_tuners and struct cs_dbs_tuners from the common governor header to the ondemand and conservative governor code, respectively, as they don't need to be in the common header any more. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:41:36 +01:00
cpufreq: conservative: Fix typos in comments Fix a couple of typos in comments. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-08 17:24:24 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
[PATCH] cpufreq_conservative: aligning of codebase with ondemand Since the conservative govenor was released its codebase has drifted from the the direction and updates that have been applied to the ondemand govornor. This patch addresses the lack of updates in that period and brings conservative back up to date. The resulting diff file between cpufreq_ondemand.c and cpufreq_conservative.c is now much smaller and shows more clearly the differences between the two. Another reason to do this is ages ago, knowingly, I did a piss poor attempt at making conservative less responsive by knocking up DEF_SAMPLING_RATE_LATENCY_MULTIPLIER by two orders of magnitude. I did fix this ages ago but in my dis-organisation I must have toasted the diff and left it the way it was. About two weeks ago a user contacted me saying he was having problems with the conservative governor with his AMD Athlon XP-M 2800+ as /sys/devices/system/cpu/cpu0/cpufreq/conservative showed sampling_rate_min 9950000 sampling_rate_max 1360065408 Nine seconds to decide about changing the frequency....not too responsive :) Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-03-22 09:54:10 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Rename get_freq_target() to get_freq_step() What's returned from this function is the delta by which the frequency must be increased or decreased and not the final frequency that should be selected. Name it properly to match its purpose. Also update the variables used to store that value. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 12:30:43 +05:30
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
cpufreq: conservative: Rename get_freq_target() to get_freq_step() What's returned from this function is the delta by which the frequency must be increased or decreased and not the final frequency that should be selected. Name it properly to match its purpose. Also update the variables used to store that value. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 12:30:43 +05:30
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
cpufreq: conservative: Rename get_freq_target() to get_freq_step() What's returned from this function is the delta by which the frequency must be increased or decreased and not the final frequency that should be selected. Name it properly to match its purpose. Also update the variables used to store that value. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 12:30:43 +05:30
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
cpufreq: conservative: Rename get_freq_target() to get_freq_step() What's returned from this function is the delta by which the frequency must be increased or decreased and not the final frequency that should be selected. Name it properly to match its purpose. Also update the variables used to store that value. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 12:30:43 +05:30
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: conservative: Fix sampling_down_factor functionality sampling_down_factor tunable is unused since commit 8e677ce83bf41ba9c74e5b6d9ee60b07d4e5ed93 (4 years ago). This patch restores the original functionality and documents the tunable. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-05 22:06:29 +00:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: conservative: Fix comment explaining frequency updates The original comment about the frequency increase to maximum is wrong. Both increase and decrease happen at steps. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 21:27:22 +02:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: Don't use 'timer' keyword The earlier implementation of governors used background timers and so functions, mutex, etc had 'timer' keyword in their names. But that's not true anymore. Replace 'timer' with 'update', as those functions, variables are based around updates to frequency. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-08 11:06:33 +05:30
[CPUFREQ] Make cpufreq_conservative handle out-of-sync events properly Make cpufreq_conservative handle out-of-sync events properly Currently, the cpufreq_conservative governor doesn't get notified when the actual frequency the cpu is running at differs from what cpufreq thought it was. As a result the cpu may stay at the maximum frequency after a s2ram / resume cycle even though the system is idle. Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 09:50:13 +02:00
cpufreq: governor: Rearrange governor data structures The struct policy_dbs_info objects representing per-policy governor data are not accessible directly from the corresponding policy objects. To access them, one has to get a pointer to the struct cpu_dbs_info of policy->cpu and use the policy_dbs field of that which isn't really straightforward. To address that rearrange the governor data structures so the governor_data pointer in struct cpufreq_policy will point to struct policy_dbs_info (instead of struct dbs_data) and that will contain a pointer to struct dbs_data. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-07 16:24:26 +01:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governor: Rearrange governor data structures The struct policy_dbs_info objects representing per-policy governor data are not accessible directly from the corresponding policy objects. To access them, one has to get a pointer to the struct cpu_dbs_info of policy->cpu and use the policy_dbs field of that which isn't really straightforward. To address that rearrange the governor data structures so the governor_data pointer in struct cpufreq_policy will point to struct policy_dbs_info (instead of struct dbs_data) and that will contain a pointer to struct dbs_data. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-07 16:24:26 +01:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: governor: Get rid of the ->gov_check_cpu callback The way the ->gov_check_cpu governor callback is used by the ondemand and conservative governors is not really straightforward. Namely, the governor calls dbs_check_cpu() that updates the load information for the policy and the invokes ->gov_check_cpu() for the governor. To get rid of that entanglement, notice that cpufreq_governor_limits() doesn't need to call dbs_check_cpu() directly. Instead, it can simply reset the sample delay to 0 which will cause a sample to be taken immediately. The result of that is practically equivalent to calling dbs_check_cpu() except that it will trigger a full update of governor internal state and not just the ->gov_check_cpu() part. Following that observation, make cpufreq_governor_limits() reset the sample delay and turn dbs_check_cpu() into a function that will simply evaluate the load and return the result called dbs_update(). That function can now be called by governors from the routines that previously were pointed to by ->gov_check_cpu and those routines can be called directly by each governor instead of dbs_check_cpu(). This way ->gov_check_cpu becomes unnecessary, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:19:31 +01:00
cpufreq: conservative: Decrease frequency faster for deferred updates Conservative governor changes the CPU frequency in steps. That means that if a CPU runs at max frequency, it will need several sampling periods to return to min frequency when the workload is finished. If the update function that calculates the load and target frequency is deferred, the governor might need even more time to decrease the frequency. This may have impact to power consumption and after all conservative should decrease the frequency if there is no workload at every sampling rate. To resolve the above issue calculate the number of sampling periods that the update is deferred. Considering that for each sampling period conservative should drop the frequency by a freq_step because the CPU was idle apply the proper subtraction to requested frequency. Below, the kernel trace with and without this patch. First an intensive workload is applied on a specific CPU. Then the workload is removed and the CPU goes to idle. WITHOUT <idle>-0 [007] dN.. 620.329153: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 620.350857: cpu_frequency: state=1700000 cpu_id=7 kworker/7:2-556 [007] .... 620.370856: cpu_frequency: state=1900000 cpu_id=7 kworker/7:2-556 [007] .... 620.390854: cpu_frequency: state=2100000 cpu_id=7 kworker/7:2-556 [007] .... 620.411853: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-556 [007] .... 620.432854: cpu_frequency: state=2400000 cpu_id=7 kworker/7:2-556 [007] .... 620.453854: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-556 [007] .... 620.494856: cpu_frequency: state=2900000 cpu_id=7 kworker/7:2-556 [007] .... 620.515856: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-556 [007] .... 620.536858: cpu_frequency: state=3300000 cpu_id=7 kworker/7:2-556 [007] .... 620.557857: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 669.591363: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 669.591939: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 669.591980: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] dN.. 669.591989: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.201224: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.221975: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 670.222016: cpu_frequency: state=3300000 cpu_id=7 <idle>-0 [007] d... 670.222026: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.234964: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.801251: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.236046: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.236073: cpu_frequency: state=3100000 cpu_id=7 <idle>-0 [007] d... 671.236112: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.393437: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.401277: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404083: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.404111: cpu_frequency: state=2900000 cpu_id=7 <idle>-0 [007] d... 671.404125: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404974: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.501180: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.995414: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.995459: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 671.995469: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.996287: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.001305: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.078374: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.078410: cpu_frequency: state=2600000 cpu_id=7 <idle>-0 [007] d... 672.078419: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.158020: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.158040: cpu_frequency: state=2400000 cpu_id=7 <idle>-0 [007] d... 672.158044: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.160038: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.234557: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237121: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.237174: cpu_frequency: state=2100000 cpu_id=7 <idle>-0 [007] d... 672.237186: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237778: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.267902: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.269860: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.269906: cpu_frequency: state=1900000 cpu_id=7 <idle>-0 [007] d... 672.269914: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.271902: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.751342: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.823056: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.823095: cpu_frequency: state=1600000 cpu_id=7 WITH <idle>-0 [007] dN.. 4380.928009: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4380.949767: cpu_frequency: state=2000000 cpu_id=7 kworker/7:2-399 [007] .... 4380.969765: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-399 [007] .... 4381.009766: cpu_frequency: state=2500000 cpu_id=7 kworker/7:2-399 [007] .... 4381.029767: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-399 [007] .... 4381.049769: cpu_frequency: state=2800000 cpu_id=7 kworker/7:2-399 [007] .... 4381.069769: cpu_frequency: state=3000000 cpu_id=7 kworker/7:2-399 [007] .... 4381.089771: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-399 [007] .... 4381.109772: cpu_frequency: state=3400000 cpu_id=7 kworker/7:2-399 [007] .... 4381.129773: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 4428.226159: cpu_idle: state=1 cpu_id=7 <idle>-0 [007] d... 4428.226176: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 4428.226181: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.227177: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.551640: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.649239: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.649268: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 4428.649278: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.689856: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.799542: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.801683: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.801748: cpu_frequency: state=1700000 cpu_id=7 <idle>-0 [007] d... 4428.801761: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.806545: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4429.051880: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4429.086240: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4429.086293: cpu_frequency: state=1600000 cpu_id=7 Without the patch the CPU dropped to min frequency after 3.2s With the patch applied the CPU dropped to min frequency after 0.86s Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 19:26:29 +02:00
[CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not locked When someone added the dbs_cpufreq_notifier section to the governor the code ended up causing the frequency to only fall. This is because requested_freq is tinkered with and that should only modified if it has an invlaid value due to changes in the available frequency ranges This should fix #10055. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-13 19:01:51 +00:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: governor: Get rid of the ->gov_check_cpu callback The way the ->gov_check_cpu governor callback is used by the ondemand and conservative governors is not really straightforward. Namely, the governor calls dbs_check_cpu() that updates the load information for the policy and the invokes ->gov_check_cpu() for the governor. To get rid of that entanglement, notice that cpufreq_governor_limits() doesn't need to call dbs_check_cpu() directly. Instead, it can simply reset the sample delay to 0 which will cause a sample to be taken immediately. The result of that is practically equivalent to calling dbs_check_cpu() except that it will trigger a full update of governor internal state and not just the ->gov_check_cpu() part. Following that observation, make cpufreq_governor_limits() reset the sample delay and turn dbs_check_cpu() into a function that will simply evaluate the load and return the result called dbs_update(). That function can now be called by governors from the routines that previously were pointed to by ->gov_check_cpu and those routines can be called directly by each governor instead of dbs_check_cpu(). This way ->gov_check_cpu becomes unnecessary, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:19:31 +01:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: conservative: Take limits changes into account properly If the policy limits change between invocations of cs_dbs_update(), the requested frequency value stored in dbs_info may not be updated and the function may use a stale value of it next time. Moreover, if idle periods are takem into account by cs_dbs_update(), the requested frequency value stored in dbs_info may be below the min policy limit, which is incorrect. To fix these problems, always update the requested frequency value in dbs_info along with the local copy of it when the previous requested frequency is beyond the policy limits and avoid decreasing the requested frequency below the min policy limit when taking idle periods into account. Fixes: abb6627910a1 (cpufreq: conservative: Fix next frequency selection) Fixes: 00bfe05889e9 (cpufreq: conservative: Decrease frequency faster for deferred updates) Reported-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-15 23:21:05 +02:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: conservative: Take limits changes into account properly If the policy limits change between invocations of cs_dbs_update(), the requested frequency value stored in dbs_info may not be updated and the function may use a stale value of it next time. Moreover, if idle periods are takem into account by cs_dbs_update(), the requested frequency value stored in dbs_info may be below the min policy limit, which is incorrect. To fix these problems, always update the requested frequency value in dbs_info along with the local copy of it when the previous requested frequency is beyond the policy limits and avoid decreasing the requested frequency below the min policy limit when taking idle periods into account. Fixes: abb6627910a1 (cpufreq: conservative: Fix next frequency selection) Fixes: 00bfe05889e9 (cpufreq: conservative: Decrease frequency faster for deferred updates) Reported-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-15 23:21:05 +02:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: conservative: Decrease frequency faster for deferred updates Conservative governor changes the CPU frequency in steps. That means that if a CPU runs at max frequency, it will need several sampling periods to return to min frequency when the workload is finished. If the update function that calculates the load and target frequency is deferred, the governor might need even more time to decrease the frequency. This may have impact to power consumption and after all conservative should decrease the frequency if there is no workload at every sampling rate. To resolve the above issue calculate the number of sampling periods that the update is deferred. Considering that for each sampling period conservative should drop the frequency by a freq_step because the CPU was idle apply the proper subtraction to requested frequency. Below, the kernel trace with and without this patch. First an intensive workload is applied on a specific CPU. Then the workload is removed and the CPU goes to idle. WITHOUT <idle>-0 [007] dN.. 620.329153: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 620.350857: cpu_frequency: state=1700000 cpu_id=7 kworker/7:2-556 [007] .... 620.370856: cpu_frequency: state=1900000 cpu_id=7 kworker/7:2-556 [007] .... 620.390854: cpu_frequency: state=2100000 cpu_id=7 kworker/7:2-556 [007] .... 620.411853: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-556 [007] .... 620.432854: cpu_frequency: state=2400000 cpu_id=7 kworker/7:2-556 [007] .... 620.453854: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-556 [007] .... 620.494856: cpu_frequency: state=2900000 cpu_id=7 kworker/7:2-556 [007] .... 620.515856: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-556 [007] .... 620.536858: cpu_frequency: state=3300000 cpu_id=7 kworker/7:2-556 [007] .... 620.557857: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 669.591363: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 669.591939: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 669.591980: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] dN.. 669.591989: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.201224: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.221975: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 670.222016: cpu_frequency: state=3300000 cpu_id=7 <idle>-0 [007] d... 670.222026: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.234964: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.801251: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.236046: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.236073: cpu_frequency: state=3100000 cpu_id=7 <idle>-0 [007] d... 671.236112: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.393437: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.401277: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404083: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.404111: cpu_frequency: state=2900000 cpu_id=7 <idle>-0 [007] d... 671.404125: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404974: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.501180: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.995414: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.995459: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 671.995469: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.996287: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.001305: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.078374: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.078410: cpu_frequency: state=2600000 cpu_id=7 <idle>-0 [007] d... 672.078419: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.158020: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.158040: cpu_frequency: state=2400000 cpu_id=7 <idle>-0 [007] d... 672.158044: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.160038: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.234557: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237121: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.237174: cpu_frequency: state=2100000 cpu_id=7 <idle>-0 [007] d... 672.237186: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237778: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.267902: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.269860: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.269906: cpu_frequency: state=1900000 cpu_id=7 <idle>-0 [007] d... 672.269914: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.271902: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.751342: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.823056: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.823095: cpu_frequency: state=1600000 cpu_id=7 WITH <idle>-0 [007] dN.. 4380.928009: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4380.949767: cpu_frequency: state=2000000 cpu_id=7 kworker/7:2-399 [007] .... 4380.969765: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-399 [007] .... 4381.009766: cpu_frequency: state=2500000 cpu_id=7 kworker/7:2-399 [007] .... 4381.029767: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-399 [007] .... 4381.049769: cpu_frequency: state=2800000 cpu_id=7 kworker/7:2-399 [007] .... 4381.069769: cpu_frequency: state=3000000 cpu_id=7 kworker/7:2-399 [007] .... 4381.089771: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-399 [007] .... 4381.109772: cpu_frequency: state=3400000 cpu_id=7 kworker/7:2-399 [007] .... 4381.129773: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 4428.226159: cpu_idle: state=1 cpu_id=7 <idle>-0 [007] d... 4428.226176: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 4428.226181: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.227177: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.551640: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.649239: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.649268: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 4428.649278: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.689856: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.799542: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.801683: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.801748: cpu_frequency: state=1700000 cpu_id=7 <idle>-0 [007] d... 4428.801761: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.806545: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4429.051880: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4429.086240: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4429.086293: cpu_frequency: state=1600000 cpu_id=7 Without the patch the CPU dropped to min frequency after 3.2s With the patch applied the CPU dropped to min frequency after 0.86s Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 19:26:29 +02:00
cpufreq: conservative: Take limits changes into account properly If the policy limits change between invocations of cs_dbs_update(), the requested frequency value stored in dbs_info may not be updated and the function may use a stale value of it next time. Moreover, if idle periods are takem into account by cs_dbs_update(), the requested frequency value stored in dbs_info may be below the min policy limit, which is incorrect. To fix these problems, always update the requested frequency value in dbs_info along with the local copy of it when the previous requested frequency is beyond the policy limits and avoid decreasing the requested frequency below the min policy limit when taking idle periods into account. Fixes: abb6627910a1 (cpufreq: conservative: Fix next frequency selection) Fixes: 00bfe05889e9 (cpufreq: conservative: Decrease frequency faster for deferred updates) Reported-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Waldemar Rymarkiewicz <waldemarx.rymarkiewicz@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-15 23:21:05 +02:00
cpufreq: conservative: Decrease frequency faster for deferred updates Conservative governor changes the CPU frequency in steps. That means that if a CPU runs at max frequency, it will need several sampling periods to return to min frequency when the workload is finished. If the update function that calculates the load and target frequency is deferred, the governor might need even more time to decrease the frequency. This may have impact to power consumption and after all conservative should decrease the frequency if there is no workload at every sampling rate. To resolve the above issue calculate the number of sampling periods that the update is deferred. Considering that for each sampling period conservative should drop the frequency by a freq_step because the CPU was idle apply the proper subtraction to requested frequency. Below, the kernel trace with and without this patch. First an intensive workload is applied on a specific CPU. Then the workload is removed and the CPU goes to idle. WITHOUT <idle>-0 [007] dN.. 620.329153: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 620.350857: cpu_frequency: state=1700000 cpu_id=7 kworker/7:2-556 [007] .... 620.370856: cpu_frequency: state=1900000 cpu_id=7 kworker/7:2-556 [007] .... 620.390854: cpu_frequency: state=2100000 cpu_id=7 kworker/7:2-556 [007] .... 620.411853: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-556 [007] .... 620.432854: cpu_frequency: state=2400000 cpu_id=7 kworker/7:2-556 [007] .... 620.453854: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-556 [007] .... 620.494856: cpu_frequency: state=2900000 cpu_id=7 kworker/7:2-556 [007] .... 620.515856: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-556 [007] .... 620.536858: cpu_frequency: state=3300000 cpu_id=7 kworker/7:2-556 [007] .... 620.557857: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 669.591363: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 669.591939: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 669.591980: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] dN.. 669.591989: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.201224: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.221975: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 670.222016: cpu_frequency: state=3300000 cpu_id=7 <idle>-0 [007] d... 670.222026: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.234964: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.801251: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.236046: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.236073: cpu_frequency: state=3100000 cpu_id=7 <idle>-0 [007] d... 671.236112: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.393437: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.401277: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404083: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.404111: cpu_frequency: state=2900000 cpu_id=7 <idle>-0 [007] d... 671.404125: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404974: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.501180: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.995414: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.995459: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 671.995469: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.996287: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.001305: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.078374: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.078410: cpu_frequency: state=2600000 cpu_id=7 <idle>-0 [007] d... 672.078419: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.158020: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.158040: cpu_frequency: state=2400000 cpu_id=7 <idle>-0 [007] d... 672.158044: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.160038: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.234557: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237121: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.237174: cpu_frequency: state=2100000 cpu_id=7 <idle>-0 [007] d... 672.237186: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237778: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.267902: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.269860: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.269906: cpu_frequency: state=1900000 cpu_id=7 <idle>-0 [007] d... 672.269914: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.271902: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.751342: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.823056: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.823095: cpu_frequency: state=1600000 cpu_id=7 WITH <idle>-0 [007] dN.. 4380.928009: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4380.949767: cpu_frequency: state=2000000 cpu_id=7 kworker/7:2-399 [007] .... 4380.969765: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-399 [007] .... 4381.009766: cpu_frequency: state=2500000 cpu_id=7 kworker/7:2-399 [007] .... 4381.029767: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-399 [007] .... 4381.049769: cpu_frequency: state=2800000 cpu_id=7 kworker/7:2-399 [007] .... 4381.069769: cpu_frequency: state=3000000 cpu_id=7 kworker/7:2-399 [007] .... 4381.089771: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-399 [007] .... 4381.109772: cpu_frequency: state=3400000 cpu_id=7 kworker/7:2-399 [007] .... 4381.129773: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 4428.226159: cpu_idle: state=1 cpu_id=7 <idle>-0 [007] d... 4428.226176: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 4428.226181: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.227177: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.551640: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.649239: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.649268: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 4428.649278: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.689856: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.799542: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.801683: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.801748: cpu_frequency: state=1700000 cpu_id=7 <idle>-0 [007] d... 4428.801761: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.806545: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4429.051880: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4429.086240: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4429.086293: cpu_frequency: state=1600000 cpu_id=7 Without the patch the CPU dropped to min frequency after 3.2s With the patch applied the CPU dropped to min frequency after 0.86s Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 19:26:29 +02:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: conservative: Decrease frequency faster for deferred updates Conservative governor changes the CPU frequency in steps. That means that if a CPU runs at max frequency, it will need several sampling periods to return to min frequency when the workload is finished. If the update function that calculates the load and target frequency is deferred, the governor might need even more time to decrease the frequency. This may have impact to power consumption and after all conservative should decrease the frequency if there is no workload at every sampling rate. To resolve the above issue calculate the number of sampling periods that the update is deferred. Considering that for each sampling period conservative should drop the frequency by a freq_step because the CPU was idle apply the proper subtraction to requested frequency. Below, the kernel trace with and without this patch. First an intensive workload is applied on a specific CPU. Then the workload is removed and the CPU goes to idle. WITHOUT <idle>-0 [007] dN.. 620.329153: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 620.350857: cpu_frequency: state=1700000 cpu_id=7 kworker/7:2-556 [007] .... 620.370856: cpu_frequency: state=1900000 cpu_id=7 kworker/7:2-556 [007] .... 620.390854: cpu_frequency: state=2100000 cpu_id=7 kworker/7:2-556 [007] .... 620.411853: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-556 [007] .... 620.432854: cpu_frequency: state=2400000 cpu_id=7 kworker/7:2-556 [007] .... 620.453854: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-556 [007] .... 620.494856: cpu_frequency: state=2900000 cpu_id=7 kworker/7:2-556 [007] .... 620.515856: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-556 [007] .... 620.536858: cpu_frequency: state=3300000 cpu_id=7 kworker/7:2-556 [007] .... 620.557857: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 669.591363: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 669.591939: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 669.591980: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] dN.. 669.591989: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.201224: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.221975: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 670.222016: cpu_frequency: state=3300000 cpu_id=7 <idle>-0 [007] d... 670.222026: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 670.234964: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 670.801251: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.236046: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.236073: cpu_frequency: state=3100000 cpu_id=7 <idle>-0 [007] d... 671.236112: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.393437: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.401277: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404083: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.404111: cpu_frequency: state=2900000 cpu_id=7 <idle>-0 [007] d... 671.404125: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.404974: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 671.501180: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.995414: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 671.995459: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 671.995469: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 671.996287: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.001305: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.078374: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.078410: cpu_frequency: state=2600000 cpu_id=7 <idle>-0 [007] d... 672.078419: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.158020: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.158040: cpu_frequency: state=2400000 cpu_id=7 <idle>-0 [007] d... 672.158044: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.160038: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.234557: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237121: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.237174: cpu_frequency: state=2100000 cpu_id=7 <idle>-0 [007] d... 672.237186: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.237778: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.267902: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.269860: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.269906: cpu_frequency: state=1900000 cpu_id=7 <idle>-0 [007] d... 672.269914: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.271902: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 672.751342: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 672.823056: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-556 [007] .... 672.823095: cpu_frequency: state=1600000 cpu_id=7 WITH <idle>-0 [007] dN.. 4380.928009: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4380.949767: cpu_frequency: state=2000000 cpu_id=7 kworker/7:2-399 [007] .... 4380.969765: cpu_frequency: state=2200000 cpu_id=7 kworker/7:2-399 [007] .... 4381.009766: cpu_frequency: state=2500000 cpu_id=7 kworker/7:2-399 [007] .... 4381.029767: cpu_frequency: state=2600000 cpu_id=7 kworker/7:2-399 [007] .... 4381.049769: cpu_frequency: state=2800000 cpu_id=7 kworker/7:2-399 [007] .... 4381.069769: cpu_frequency: state=3000000 cpu_id=7 kworker/7:2-399 [007] .... 4381.089771: cpu_frequency: state=3100000 cpu_id=7 kworker/7:2-399 [007] .... 4381.109772: cpu_frequency: state=3400000 cpu_id=7 kworker/7:2-399 [007] .... 4381.129773: cpu_frequency: state=3401000 cpu_id=7 <idle>-0 [007] d... 4428.226159: cpu_idle: state=1 cpu_id=7 <idle>-0 [007] d... 4428.226176: cpu_idle: state=4294967295 cpu_id=7 <idle>-0 [007] d... 4428.226181: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.227177: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.551640: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.649239: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.649268: cpu_frequency: state=2800000 cpu_id=7 <idle>-0 [007] d... 4428.649278: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.689856: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4428.799542: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.801683: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4428.801748: cpu_frequency: state=1700000 cpu_id=7 <idle>-0 [007] d... 4428.801761: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4428.806545: cpu_idle: state=4294967295 cpu_id=7 ... <idle>-0 [007] d... 4429.051880: cpu_idle: state=4 cpu_id=7 <idle>-0 [007] d... 4429.086240: cpu_idle: state=4294967295 cpu_id=7 kworker/7:2-399 [007] .... 4429.086293: cpu_frequency: state=1600000 cpu_id=7 Without the patch the CPU dropped to min frequency after 3.2s With the patch applied the CPU dropped to min frequency after 0.86s Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-16 19:26:29 +02:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: Use CPUFREQ_RELATION_E in DVFS governors Let the governors schedutil, conservative and ondemand to work, if possible on efficient frequencies only. Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-09-08 15:05:29 +01:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governor: Get rid of the ->gov_check_cpu callback The way the ->gov_check_cpu governor callback is used by the ondemand and conservative governors is not really straightforward. Namely, the governor calls dbs_check_cpu() that updates the load information for the policy and the invokes ->gov_check_cpu() for the governor. To get rid of that entanglement, notice that cpufreq_governor_limits() doesn't need to call dbs_check_cpu() directly. Instead, it can simply reset the sample delay to 0 which will cause a sample to be taken immediately. The result of that is practically equivalent to calling dbs_check_cpu() except that it will trigger a full update of governor internal state and not just the ->gov_check_cpu() part. Following that observation, make cpufreq_governor_limits() reset the sample delay and turn dbs_check_cpu() into a function that will simply evaluate the load and return the result called dbs_update(). That function can now be called by governors from the routines that previously were pointed to by ->gov_check_cpu and those routines can be called directly by each governor instead of dbs_check_cpu(). This way ->gov_check_cpu becomes unnecessary, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:19:31 +01:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: conservative: Fix sampling_down_factor functionality sampling_down_factor tunable is unused since commit 8e677ce83bf41ba9c74e5b6d9ee60b07d4e5ed93 (4 years ago). This patch restores the original functionality and documents the tunable. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-05 22:06:29 +00:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
cpufreq: governor: Get rid of the ->gov_check_cpu callback The way the ->gov_check_cpu governor callback is used by the ondemand and conservative governors is not really straightforward. Namely, the governor calls dbs_check_cpu() that updates the load information for the policy and the invokes ->gov_check_cpu() for the governor. To get rid of that entanglement, notice that cpufreq_governor_limits() doesn't need to call dbs_check_cpu() directly. Instead, it can simply reset the sample delay to 0 which will cause a sample to be taken immediately. The result of that is practically equivalent to calling dbs_check_cpu() except that it will trigger a full update of governor internal state and not just the ->gov_check_cpu() part. Following that observation, make cpufreq_governor_limits() reset the sample delay and turn dbs_check_cpu() into a function that will simply evaluate the load and return the result called dbs_update(). That function can now be called by governors from the routines that previously were pointed to by ->gov_check_cpu and those routines can be called directly by each governor instead of dbs_check_cpu(). This way ->gov_check_cpu becomes unnecessary, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:19:31 +01:00
cpufreq: conservative: Fix sampling_down_factor functionality sampling_down_factor tunable is unused since commit 8e677ce83bf41ba9c74e5b6d9ee60b07d4e5ed93 (4 years ago). This patch restores the original functionality and documents the tunable. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-05 22:06:29 +00:00
cpufreq: conservative: Fix the logic in frequency decrease checking When we evaluate the CPU load for frequency decrease we have to compare the load against down_threshold. There is no need to subtract 10 points from down_threshold. Instead, we have to use the default down_threshold or user's selection unmodified. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-05 22:06:40 +00:00
cpufreq: conservative: Simplify frequency limit handling cs_dbs_update() performs explicit checks against policy->min/max before updating the target frequency. These checks are redundant as __cpufreq_driver_target() already clamps the requested frequency to the valid policy limits. Remove the unnecessary boundary checks and simplify the update logic. This also fixes an issue introduced by commit 00bfe05889e9 ("cpufreq: conservative: Decrease frequency faster for deferred updates"), where stale target comparisons could cause frequency updates to be skipped entirely after deferred adjustments. Closes: https://lore.kernel.org/all/20260421123545.1745998-1-zhenglifeng1@huawei.com/ Fixes: 00bfe05889e9 ("cpufreq: conservative: Decrease frequency faster for deferred updates") Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Co-developed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Link: https://patch.msgid.link/292e6d937890f135e30ec0d2107eaad47cb9a976.1779423281.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-05-22 09:49:10 +05:30
cpufreq: conservative: Rename get_freq_target() to get_freq_step() What's returned from this function is the delta by which the frequency must be increased or decreased and not the final frequency that should be selected. Name it properly to match its purpose. Also update the variables used to store that value. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 12:30:43 +05:30
cpufreq: conservative: fix requested_freq reduction issue When decreasing frequency, requested_freq may be less than freq_target, So requested_freq minus freq_target may be negative, But reqested_freq's unit is unsigned int, then the negative result will be one larger interger which may be even higher than requested_freq. This patch is to fix such issue. when result becomes negative, set requested_freq as the min value of policy. Signed-off-by: Xiaoguang Chen <chenxg@marvell.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-07 10:28:50 +08:00
cpufreq: conservative: Do not use transition notifications The conservative governor registers a transition notifier so it can update its internal requested_freq value if it falls out of the policy->min...policy->max range, but requested_freq is not really necessary. That value is used to track the frequency requested by the governor previously, but policy->cur can be used instead of it and then the governor will not have to worry about updating the tracked value when the current frequency changes independently (for example, as a result of min or max changes). Accodringly, drop requested_freq from struct cs_policy_dbs_info and modify cs_dbs_timer() to use policy->cur instead of it. While at it, notice that __cpufreq_driver_target() clamps its target_freq argument between policy->min and policy->max, so the callers of it don't have to do that and make additional changes in cs_dbs_timer() in accordance with that. After these changes the transition notifier used by the conservative governor is not necessary any more, so drop it, which also makes it possible to drop the struct cs_governor definition and simplify the code accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-06-13 23:33:49 +02:00
cpufreq: conservative: Break out earlier on the lowest frequency If we're on the lowest frequency, no need to calculate new freq. Break out even earlier in this case. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-28 05:38:01 +00:00
cpufreq: Use CPUFREQ_RELATION_E in DVFS governors Let the governors schedutil, conservative and ondemand to work, if possible on efficient frequencies only. Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-09-08 15:05:29 +01:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: Get rid of the ->gov_check_cpu callback The way the ->gov_check_cpu governor callback is used by the ondemand and conservative governors is not really straightforward. Namely, the governor calls dbs_check_cpu() that updates the load information for the policy and the invokes ->gov_check_cpu() for the governor. To get rid of that entanglement, notice that cpufreq_governor_limits() doesn't need to call dbs_check_cpu() directly. Instead, it can simply reset the sample delay to 0 which will cause a sample to be taken immediately. The result of that is practically equivalent to calling dbs_check_cpu() except that it will trigger a full update of governor internal state and not just the ->gov_check_cpu() part. Following that observation, make cpufreq_governor_limits() reset the sample delay and turn dbs_check_cpu() into a function that will simply evaluate the load and return the result called dbs_update(). That function can now be called by governors from the routines that previously were pointed to by ->gov_check_cpu and those routines can be called directly by each governor instead of dbs_check_cpu(). This way ->gov_check_cpu becomes unnecessary, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:19:31 +01:00
cpufreq: governor: Use microseconds in sample delay computations Do not convert microseconds to jiffies and the other way around in governor computations related to the sampling rate and sample delay and drop delay_for_sampling_rate() which isn't of any use then. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-15 02:22:13 +01:00
cpufreq: conservative: call dbs_check_cpu only when necessary Modify conservative timer to not resample CPU utilization if recently sampled from another SW coordinated core. Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-12-27 14:55:41 +00:00
cpufreq: governors: Remove code redundancy between governors With the inclusion of following patches: 9f4eb10 cpufreq: conservative: call dbs_check_cpu only when necessary 772b4b1 cpufreq: ondemand: call dbs_check_cpu only when necessary code redundancy between the conservative and ondemand governors is introduced again, so get rid of it. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-01-31 17:28:02 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: unify show() and store() naming and use __ATTR_XX Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-10 22:38:30 +08:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] conservative: fixup governor to function more like ondemand logic As conservative is based off ondemand the codebases occasionally need to be resync'd. This patch, although ugly, does this. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-13 19:02:34 +00:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: unify show() and store() naming and use __ATTR_XX Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-10 22:38:30 +08:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: unify show() and store() naming and use __ATTR_XX Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-10 22:38:30 +08:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Allow down_threshold to take values from 1 to 10 Commit 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency decrease checking) removed the 10 point substraction when comparing the load against down_threshold but did not remove the related limit for the down_threshold value. As a result, down_threshold lower than 11 is not allowed even though values from 1 to 10 do work correctly too. The comment ("cannot be lower than 11 otherwise freq will not fall") also does not apply after removing the substraction. For this reason, allow down_threshold to take any value from 1 to 99 and fix the related comment. Fixes: 27ed3cd2ebf4 (cpufreq: conservative: Fix the logic in frequency decrease checking) Signed-off-by: Tomasz Wilczyński <twilczynski@naver.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-11 17:28:39 +09:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: unify show() and store() naming and use __ATTR_XX Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-10 22:38:30 +08:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
cpufreq: governor: Fix CPU load information updates via ->store The ->store() callbacks of some tunable sysfs attributes of the ondemand and conservative governors trigger immediate updates of the CPU load information for all CPUs "governed" by the given dbs_data by walking the cpu_dbs_info structures for all online CPUs in the system and updating them. This is questionable for two reasons. First, it may lead to a lot of extra overhead on a system with many CPUs if the given dbs_data is only associated with a few of them. Second, if governor tunables are per-policy, the CPUs associated with the other sets of governor tunables should not be updated. To address this issue, use the observation that in all of the places in question the update operation may be carried out in the same way (because all of the tunables involved are now located in struct dbs_data and readily available to the common code) and make the code in those places invoke the same (new) helper function that will carry out the update correctly. That new function always checks the ignore_nice_load tunable value and updates the CPUs' prev_cpu_nice data fields if that's set, which wasn't done by the original code in store_io_is_busy(), but it should have been done in there too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 02:26:55 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] Fix up whitespace in conservative governor. Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:49:09 -04:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] Fix up whitespace in conservative governor. Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:49:09 -04:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] Remove unneeded locks There cannot be any concurrent access to these through different cpu sysfs files anymore, because these tunables are now all global (not per cpu). I still have some doubts whether some of these locks were needed at all. Anyway, let's get rid of them. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com> CC: cpufreq@vger.kernel.org
2011-03-03 21:31:27 +01:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] conservative: fixup governor to function more like ondemand logic As conservative is based off ondemand the codebases occasionally need to be resync'd. This patch, although ugly, does this. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-13 19:02:34 +00:00
cpufreq: governor: Move per-CPU data to the common code After previous changes there is only one piece of code in the ondemand governor making references to per-CPU data structures, but it can be easily modified to avoid doing that, so modify it accordingly and move the definition of per-CPU data used by the ondemand and conservative governors to the common code. Next, change that code to access the per-CPU data structures directly rather than via a governor callback. This causes the ->get_cpu_cdbs governor callback to become unnecessary, so drop it along with the macro and function definitions related to it. Finally, drop the definitions of struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s that aren't necessary any more. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-21 00:51:27 +01:00
cpufreq: governor: Fix CPU load information updates via ->store The ->store() callbacks of some tunable sysfs attributes of the ondemand and conservative governors trigger immediate updates of the CPU load information for all CPUs "governed" by the given dbs_data by walking the cpu_dbs_info structures for all online CPUs in the system and updating them. This is questionable for two reasons. First, it may lead to a lot of extra overhead on a system with many CPUs if the given dbs_data is only associated with a few of them. Second, if governor tunables are per-policy, the CPUs associated with the other sets of governor tunables should not be updated. To address this issue, use the observation that in all of the places in question the update operation may be carried out in the same way (because all of the tunables involved are now located in struct dbs_data and readily available to the common code) and make the code in those places invoke the same (new) helper function that will carry out the update correctly. That new function always checks the ignore_nice_load tunable value and updates the CPUs' prev_cpu_nice data fields if that's set, which wasn't done by the original code in store_io_is_busy(), but it should have been done in there too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 02:26:55 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: unify show() and store() naming and use __ATTR_XX Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang <zhanglianjie@uniontech.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-03-10 22:38:30 +08:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New data type for management part of dbs_data In addition to fields representing governor tunables, struct dbs_data contains some fields needed for the management of objects of that type. As it turns out, that part of struct dbs_data may be shared with (future) governors that won't use the common code used by "ondemand" and "conservative", so move it to a separate struct type and modify the code using struct dbs_data to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-22 02:47:51 +01:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: conservative: Replace sscanf() with kstrtouint() Replace sscanf() with kstrtouint() in all sysfs store functions to improve input validation and security. The kstrtouint() function provides better error detection, overflow protection, and consistent error handling compared to sscanf(). This maintains existing functionality while improving input validation robustness and following kernel coding best practices for string parsing. Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250906115316.3010384-1-kaushlendra.kumar@intel.com [ rjw: Dropped duplicate paragraph from the changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-06 17:23:16 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] Fix up whitespace in conservative governor. Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:49:09 -04:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] Fix up whitespace in conservative governor. Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:49:09 -04:00
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: New sysfs show/store callbacks for governor tunables The ondemand and conservative governors use the global-attr or freq-attr structures to represent sysfs attributes corresponding to their tunables (which of them is actually used depends on whether or not different policy objects can use the same governor with different tunables at the same time and, consequently, on where those attributes are located in sysfs). Unfortunately, in the freq-attr case, the standard cpufreq show/store sysfs attribute callbacks are applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That may lead to an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. Therefore policy->rwsem cannot be dropped in cpufreq_set_policy() at any point, but the deadlock situation described above must be avoided too. To that end, use the observation that in principle governor tunables may be represented by the same data type regardless of whether the governor is system-wide or per-policy and introduce a new structure, struct governor_attr, for representing them and new corresponding macros for creating show/store sysfs callbacks for them. Also make their parent kobject use a new kobject type whose default show/store callbacks are not related to the standard core cpufreq ones in any way (and they don't acquire policy->rwsem in particular). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog + rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:33 +05:30
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
cpufreq: governor: New sysfs show/store callbacks for governor tunables The ondemand and conservative governors use the global-attr or freq-attr structures to represent sysfs attributes corresponding to their tunables (which of them is actually used depends on whether or not different policy objects can use the same governor with different tunables at the same time and, consequently, on where those attributes are located in sysfs). Unfortunately, in the freq-attr case, the standard cpufreq show/store sysfs attribute callbacks are applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That may lead to an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. Therefore policy->rwsem cannot be dropped in cpufreq_set_policy() at any point, but the deadlock situation described above must be avoided too. To that end, use the observation that in principle governor tunables may be represented by the same data type regardless of whether the governor is system-wide or per-policy and introduce a new structure, struct governor_attr, for representing them and new corresponding macros for creating show/store sysfs callbacks for them. Also make their parent kobject use a new kobject type whose default show/store callbacks are not related to the standard core cpufreq ones in any way (and they don't acquire policy->rwsem in particular). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog + rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:33 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: use default_groups in kobj_type There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the cpufreq code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-28 14:19:12 +01:00
cpufreq: governor: New sysfs show/store callbacks for governor tunables The ondemand and conservative governors use the global-attr or freq-attr structures to represent sysfs attributes corresponding to their tunables (which of them is actually used depends on whether or not different policy objects can use the same governor with different tunables at the same time and, consequently, on where those attributes are located in sysfs). Unfortunately, in the freq-attr case, the standard cpufreq show/store sysfs attribute callbacks are applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That may lead to an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. Therefore policy->rwsem cannot be dropped in cpufreq_set_policy() at any point, but the deadlock situation described above must be avoided too. To that end, use the observation that in principle governor tunables may be represented by the same data type regardless of whether the governor is system-wide or per-policy and introduce a new structure, struct governor_attr, for representing them and new corresponding macros for creating show/store sysfs callbacks for them. Also make their parent kobject use a new kobject type whose default show/store callbacks are not related to the standard core cpufreq ones in any way (and they don't acquire policy->rwsem in particular). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog + rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:33 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: use default_groups in kobj_type There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the cpufreq code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-28 14:19:12 +01:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
Convert 'alloc_obj' family to use the new default GFP_KERNEL argument This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 16:37:42 -08:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
cpufreq: Drop the 'initialized' field from struct cpufreq_governor The 'initialized' field in struct cpufreq_governor is only used by the conservative governor (as a usage counter) and the way that happens is far from straightforward and arguably incorrect. Namely, the value of 'initialized' is checked by cpufreq_dbs_governor_init() and cpufreq_dbs_governor_exit() and the results of those checks are passed (as the second argument) to the ->init() and ->exit() callbacks in struct dbs_governor. Those callbacks are only implemented by the ondemand and conservative governors and ondemand doesn't use their second argument at all. In turn, the conservative governor uses it to decide whether or not to either register or unregister a transition notifier. That whole mechanism is not only unnecessarily convoluted, but also racy, because the 'initialized' field of struct cpufreq_governor is updated in cpufreq_init_governor() and cpufreq_exit_governor() under policy->rwsem which doesn't help if one of these functions is run twice in parallel for different policies (which isn't impossible in principle), for example. Instead of it, add a proper usage counter to the conservative governor and update it from cs_init() and cs_exit() which is guaranteed to be non-racy, as those functions are only called under gov_dbs_data_mutex which is global. With that in place, drop the 'initialized' field from struct cpufreq_governor as it is not used any more. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-05-18 22:59:49 +02:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
Convert 'alloc_obj' family to use the new default GFP_KERNEL argument This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 16:37:42 -08:00
cpufreq: governor: Remove prints from allocation failures These aren't required anymore as the allocation core already prints such messages. Remove the redundant ones. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-18 17:55:26 +05:30
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: conservative: Use an inline function to evaluate freq_target Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-22 08:03:17 +00:00
cpufreq: governor: Move common tunables to 'struct dbs_data' There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-09 09:01:32 +05:30
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: governor: register notifier from cs_init() Notifiers are required only for conservative governor and the common governor code is unnecessarily polluted with that. Handle that from cs_init/exit() instead of cpufreq_governor_dbs(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-03 15:57:11 +05:30
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: Drop the 'initialized' field from struct cpufreq_governor The 'initialized' field in struct cpufreq_governor is only used by the conservative governor (as a usage counter) and the way that happens is far from straightforward and arguably incorrect. Namely, the value of 'initialized' is checked by cpufreq_dbs_governor_init() and cpufreq_dbs_governor_exit() and the results of those checks are passed (as the second argument) to the ->init() and ->exit() callbacks in struct dbs_governor. Those callbacks are only implemented by the ondemand and conservative governors and ondemand doesn't use their second argument at all. In turn, the conservative governor uses it to decide whether or not to either register or unregister a transition notifier. That whole mechanism is not only unnecessarily convoluted, but also racy, because the 'initialized' field of struct cpufreq_governor is updated in cpufreq_init_governor() and cpufreq_exit_governor() under policy->rwsem which doesn't help if one of these functions is run twice in parallel for different policies (which isn't impossible in principle), for example. Instead of it, add a proper usage counter to the conservative governor and update it from cs_init() and cs_exit() which is guaranteed to be non-racy, as those functions are only called under gov_dbs_data_mutex which is global. With that in place, drop the 'initialized' field from struct cpufreq_governor as it is not used any more. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-05-18 22:59:49 +02:00
cpufreq: governor: Implement per policy instances of governors Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-27 15:58:58 +00:00
cpufreq: governor: Add a ->start callback for governors To avoid having to check the governor type explicitly in the common code in order to initialize data structures specific to the governor type properly, add a ->start callback to struct dbs_governor and use it to initialize those data structures for the ondemand and conservative governors. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 02:21:21 +01:00
cpufreq: governor: Make governor private data per-policy Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s are only used for a limited set of CPUs. Namely, if a policy is shared between multiple CPUs, those fields will only be used for one of them (policy->cpu). This means that they really are per-policy rather than per-CPU and holding room for them in per-CPU data structures is generally wasteful. Also moving those fields into per-policy data structures will allow some significant simplifications to be made going forward. For this reason, introduce struct cs_policy_dbs_info and struct od_policy_dbs_info to hold those fields. Define each of the new structures as an extension of struct policy_dbs_info (such that struct policy_dbs_info is embedded in each of them) and introduce new ->alloc and ->free governor callbacks to allocate and free those structures, respectively, such that ->alloc() will return a pointer to the struct policy_dbs_info embedded in the allocated data structure and ->free() will take that pointer as its argument. With that, modify the code accessing the data fields in question in per-CPU data objects to look for them in the new structures via the struct policy_dbs_info pointer available to it and drop them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 18:40:14 +01:00
cpufreq: governor: Add a ->start callback for governors To avoid having to check the governor type explicitly in the common code in order to initialize data structures specific to the governor type properly, add a ->start callback to struct dbs_governor and use it to initialize those data structures for the ondemand and conservative governors. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 02:21:21 +01:00
cpufreq: conservative: Fix next frequency selection Commit d352cf47d93e (cpufreq: conservative: Do not use transition notifications) overlooked the case when the "frequency step" used by the conservative governor is small relative to the distances between the available frequencies and broke the algorithm by using policy->cur instead of the previously requested frequency when computing the next one. As a result, the governor may not be able to go outside of a narrow range between two consecutive available frequencies. Fix the problem by making the governor save the previously requested frequency and select the next one relative that value (unless it is out of range, in which case policy->cur will be used instead). Fixes: d352cf47d93e (cpufreq: conservative: Do not use transition notifications) Link: https://bugzilla.kernel.org/show_bug.cgi?id=177171 Reported-and-tested-by: Aleksey Rybalkin <aleksey@rybalkin.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-12 21:47:03 +02:00
cpufreq: governor: Add a ->start callback for governors To avoid having to check the governor type explicitly in the common code in order to initialize data structures specific to the governor type properly, add a ->start callback to struct dbs_governor and use it to initialize those data structures for the ondemand and conservative governors. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-18 02:21:21 +01:00
cpufreq: conservative: Reset requested_freq on limits change A recently reported issue highlighted that the cached requested_freq is not guaranteed to stay in sync with policy->cur. If the platform changes the actual CPU frequency after the governor sets one (e.g. due to platform-specific frequency scaling) and a re-sync occurs later, policy->cur may diverge from requested_freq. This can lead to incorrect behavior in the conservative governor. For example, the governor may assume the CPU is already running at the maximum frequency and skip further increases even though there is still headroom. Avoid this by resetting the cached requested_freq to policy->cur on detecting a change in policy limits. Reported-by: Lifeng Zheng <zhenglifeng1@huawei.com> Tested-by: Lifeng Zheng <zhenglifeng1@huawei.com> Link: https://lore.kernel.org/all/20260210115458.3493646-1-zhenglifeng1@huawei.com/ Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Cc: All applicable <stable@vger.kernel.org> Link: https://patch.msgid.link/d846a141a98ac0482f20560fcd7525c0f0ec2f30.1773999467.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-03-20 15:08:14 +05:30
cpufreq: conservative: Do not use transition notifications The conservative governor registers a transition notifier so it can update its internal requested_freq value if it falls out of the policy->min...policy->max range, but requested_freq is not really necessary. That value is used to track the frequency requested by the governor previously, but policy->cur can be used instead of it and then the governor will not have to worry about updating the tracked value when the current frequency changes independently (for example, as a result of min or max changes). Accodringly, drop requested_freq from struct cs_policy_dbs_info and modify cs_dbs_timer() to use policy->cur instead of it. While at it, notice that __cpufreq_driver_target() clamps its target_freq argument between policy->min and policy->max, so the callers of it don't have to do that and make additional changes in cs_dbs_timer() in accordance with that. After these changes the transition notifier used by the conservative governor is not necessary any more, so drop it, which also makes it possible to drop the struct cs_governor definition and simplify the code accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-06-13 23:33:49 +02:00
cpufreq: use default_groups in kobj_type There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the cpufreq code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-28 14:19:12 +01:00
cpufreq: governor: Don't use 'timer' keyword The earlier implementation of governors used background timers and so functions, mutex, etc had 'timer' keyword in their names. But that's not true anymore. Replace 'timer' with 'update', as those functions, variables are based around updates to frequency. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-08 11:06:33 +05:30
cpufreq: conservative: Do not use transition notifications The conservative governor registers a transition notifier so it can update its internal requested_freq value if it falls out of the policy->min...policy->max range, but requested_freq is not really necessary. That value is used to track the frequency requested by the governor previously, but policy->cur can be used instead of it and then the governor will not have to worry about updating the tracked value when the current frequency changes independently (for example, as a result of min or max changes). Accodringly, drop requested_freq from struct cs_policy_dbs_info and modify cs_dbs_timer() to use policy->cur instead of it. While at it, notice that __cpufreq_driver_target() clamps its target_freq argument between policy->min and policy->max, so the callers of it don't have to do that and make additional changes in cs_dbs_timer() in accordance with that. After these changes the transition notifier used by the conservative governor is not necessary any more, so drop it, which also makes it possible to drop the struct cs_governor definition and simplify the code accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-06-13 23:33:49 +02:00
cpufreq: conservative: Reset requested_freq on limits change A recently reported issue highlighted that the cached requested_freq is not guaranteed to stay in sync with policy->cur. If the platform changes the actual CPU frequency after the governor sets one (e.g. due to platform-specific frequency scaling) and a re-sync occurs later, policy->cur may diverge from requested_freq. This can lead to incorrect behavior in the conservative governor. For example, the governor may assume the CPU is already running at the maximum frequency and skip further increases even though there is still headroom. Avoid this by resetting the cached requested_freq to policy->cur on detecting a change in policy limits. Reported-by: Lifeng Zheng <zhenglifeng1@huawei.com> Tested-by: Lifeng Zheng <zhenglifeng1@huawei.com> Link: https://lore.kernel.org/all/20260210115458.3493646-1-zhenglifeng1@huawei.com/ Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> Cc: All applicable <stable@vger.kernel.org> Link: https://patch.msgid.link/d846a141a98ac0482f20560fcd7525c0f0ec2f30.1773999467.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-03-20 15:08:14 +05:30
cpufreq: governors: remove redundant code Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-26 00:47:42 +02:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: Register governors at core_initcall Currently, most CPUFreq governors are registered at the core_initcall time when the given governor is the default one, and the module_init time otherwise. In preparation for letting users specify the default governor on the kernel command line, change all of them to be registered at the core_initcall unconditionally, as it is already the case for the schedutil and performance governors. This will allow us to assume that builtin governors have been registered before the built-in CPUFreq drivers probe. And since all governors have similar init/exit patterns now, introduce two new macros, cpufreq_governor_{init,exit}(), to factorize the code. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-29 13:54:59 +05:30
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] conservative: amend author's email address Amend author's email address. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-13 19:01:01 +00:00
[CPUFREQ] checkpatch cleanups for conservative governor Signed-off-by: Dave Jones <davej@redhat.com>
2009-01-18 01:39:51 -05:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
[CPUFREQ] checkpatch cleanups for conservative governor Signed-off-by: Dave Jones <davej@redhat.com>
2009-01-18 01:39:51 -05:00
[CPUFREQ] Conservative cpufreq governer A new cpufreq module, based on the ondemand one with my additional patches just posted. This one is more suitable for battery environments where its probably more appealing to have the cpu freq gracefully increase and decrease rather than flip between the min and max freq's. N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency between min and max freq transition, due to the step-by-step requirements (200MHz IIRC)"; so AMD64 users would probably benefit from this too. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2005-05-31 19:03:47 -07:00
cpufreq: Initialise default governor before use When the cpufreq driver starts up at boot time, it calls into the default governor which might not be initialised yet. This hurts when the governor's worker function relies on memory that is not yet set up by its init function. This migrates all governors from module_init() to fs_initcall() when being the default, as was already done in cpufreq_performance when it was the only possible choice. The performance governor is always initialized early because it might be used as fallback even when not being the default. Fixes at least one actual oops where ondemand is the default governor and cpufreq_governor_dbs() uses the uninitialised kondemand_wq work-queue during boot-time. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-17 15:21:08 -08:00
cpufreq: Clean up default and fallback governor setup The preprocessor magic used for setting the default cpufreq governor (and for using the performance governor as a fallback one for that matter) is really nasty, so replace it with __weak functions and overrides. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-05 02:37:42 +01:00
cpufreq: Register governors at core_initcall Currently, most CPUFreq governors are registered at the core_initcall time when the given governor is the default one, and the module_init time otherwise. In preparation for letting users specify the default governor on the kernel command line, change all of them to be registered at the core_initcall unconditionally, as it is already the case for the schedutil and performance governors. This will allow us to assume that builtin governors have been registered before the built-in CPUFreq drivers probe. And since all governors have similar init/exit patterns now, introduce two new macros, cpufreq_governor_{init,exit}(), to factorize the code. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-29 13:54:59 +05:30
cpufreq: Clean up default and fallback governor setup The preprocessor magic used for setting the default cpufreq governor (and for using the performance governor as a fallback one for that matter) is really nasty, so replace it with __weak functions and overrides. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-05 02:37:42 +01:00
cpufreq: Initialise default governor before use When the cpufreq driver starts up at boot time, it calls into the default governor which might not be initialised yet. This hurts when the governor's worker function relies on memory that is not yet set up by its init function. This migrates all governors from module_init() to fs_initcall() when being the default, as was already done in cpufreq_performance when it was the only possible choice. The performance governor is always initialized early because it might be used as fallback even when not being the default. Fixes at least one actual oops where ondemand is the default governor and cpufreq_governor_dbs() uses the uninitialised kondemand_wq work-queue during boot-time. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-17 15:21:08 -08:00
cpufreq: Register governors at core_initcall Currently, most CPUFreq governors are registered at the core_initcall time when the given governor is the default one, and the module_init time otherwise. In preparation for letting users specify the default governor on the kernel command line, change all of them to be registered at the core_initcall unconditionally, as it is already the case for the schedutil and performance governors. This will allow us to assume that builtin governors have been registered before the built-in CPUFreq drivers probe. And since all governors have similar init/exit patterns now, introduce two new macros, cpufreq_governor_{init,exit}(), to factorize the code. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-29 13:54:59 +05:30