Allows collecting events system wide and then pulling out events for a
specific task name(s). e.g,
perf script -c gnome-shell,gnome-terminal
Applies on top of:
https://lkml.org/lkml/2011/11/13/74
v2->v3
- update Documentation
v1->v2
- use comm_list from symbol_conf
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1321894972-24246-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently the meaning of -C varies by perf command: for perf-top,
perf-stat, perf-record it means cpu list. For perf-report it means comm
list. Then perf-annotate, perf-report and perf-script use -c for cpu
list.
Fix annotate, report and script to use -C for cpu list to be consistent
with top, stat and record. This means report needs to use -c for comm
list which does introduce a backward compatibility change.
v1 -> v2
- update perf-script.txt too
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1321209008-7004-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use its 'perf_tool' base class instead.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-i33q40wwvk2zna8fd36ex6sm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To better reflect that it became the base class for all tools, that must
be in each tool struct and where common stuff will be put.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qgpc4msetqlwr8y2k7537cxe@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reducing the exposure of perf_session further, so that we can use the
classes in cases where no perf.data file is created.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-stua66dcscsezzrcdugvbmvd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that we don't need to have that many globals.
Next steps will remove the 'session' pointer, that in most cases is
not needed.
Then we can rename perf_event_ops to 'perf_tool' that better describes
this class hierarchy.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-wp4djox7x6w1i2bab1pt4xxp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Paving the way to remove these globals when we change the perf_event_ops
to receive as a first parameter a pointer to a perf_event_ops that will
then provide access to perf_annotate via container_of.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-xduzibqrdg3h5cttmk6p5wwc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Paving the way to remove these globals when we change the perf_event_ops
to receive as a first parameter a pointer to a perf_event_ops that will
then provide access to perf_report via container_of.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2eh2vi2nb5z3tg1lvoxv09xu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Eventually session->sample_type will go away as we want to support
multiple sample types per session, so use it from the evsel which is a
step in that direction.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-0vwdpjcwbjezw459lw5n3ew1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since we have it in evsel->hists.callchain_cursor, remove it from
perf_session.
One more step in disentangling several places from requiring a
perf_session pointer.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-rxr5dj3di7ckyfmnz0naku1z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Removing another case where a perf_session is required when processing
events.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ug1wtjbnva4bxwknflkkrlrh@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We will need this when not using perf_session in cases like 'perf top'
and strace where no perf.data file is created nor consumed.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-za923wjc41q5xot5vrhuhj3j@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since symbol__alloc_hists need it, to avoid passing it around in many
functions have it in the symbol_conf struct.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-cwv8ysvpywzjq4v3xtbd4zwv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Happens in a perf.data file where one of the events had no samples.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-j7st3oyiotvfxqde2nc41kxb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used in other tools to share the command line parsing code.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-8x0yr77r6lrd2t699s499m8n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'machine' abstraction was introduced with 'perf kvm' where we could
have samples for the host and multiple guests, but at the time we ended
up keeping the list of all machines threads all in
session->host_machine.
Move the threads rb_tree to struct machine to separate the namespaces.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mdg7sm6j3va09vtgj49gbsrp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tools being developed will need this to allow the user to override this
value.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zydc1yhxfm0z35fuy95bsn1l@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Every tool that calls this and allows the user to override the value
needs this logic.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-lwscxpg57xfzahz5dmdfp9uz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that we can easily start a workload in other tools.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-zdsksd4aphu0nltg2lpwsw3x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Out of the code in 'perf record', so that we can share option parsing,
etc. Eventually will be used by 'perf top', but first 'trace' will use
it.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-hzjqsgnte1esk90ytq0ap98v@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Convenient way of asking for tracepoint events to be added to an
existing evlist.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-0ylj4wrg54791u0baqb9swbb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Replacing the open coded equivalents in 'perf stat'.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1btwadnf2tds2g07hsccsdse@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We don't need to have two PATH_MAX char sized arrays holding it, just
one in util/debugfs.c will do.
Also rename debugfs_path to tracing_events_path, as it is not the path
to debugfs, that is debugfs_mountpoint. Both are now accessible.
This will allow accessing this code in the perf python binding without
having to drag in perf.c and util/parse-events.c.
The defaults for these variables are the canonical "/sys/kernel/debug"
and "/sys/kernel/debug/tracing/events/", removing the need for simple
tools to call debugfs_mount(NULL).
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ug9jvtjrsqbluuhqqxpvg30f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
No need for multiple definitions for STR() and die(), also use SuSv2's
PATH_MAX instead of adding MAX_PATH.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-qpujjkw7u0bf0tr4wt55cr9y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch converts virtual and userspace regulator consumer drivers to use the
module_platform_driver() macro which makes the code smaller and a bit simpler.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The implementation in aat2870_update() already did the bitwise and operation
against mask parameter.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
In current implementation, the pointer ri is not NULL if no id is matched.
Fix it by checking i == ARRAY_SIZE(aat2870_regulators) if no id is matched.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Make it is safe to assign the return value of this function
to u8/u16 variables.
Signed-off-by: Christian Hitz <christian.hitz@aizo.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Using a configuration structure simplify the finding of SoC
dependent parameters. Both platform data and device tree ids are
using these structures.
This will separate data from code and remove the need for an enum.
Idea from Grant Likely.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Trivial form modification to unify structure look.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Commit af0c25c487 ("staging: remove obsoleted CS5535/CS5536 GPIO
driver") dropped CS5535_GPIO. So this last reference to CS5535_GPIO has
been an (inconsequential) nop since v3.1. Drop it too.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Some HID devices, such as my Bluetooth mouse, report their battery
strength as an event. Rather than passing it through as a strange
absolute input event, this patch registers it with the power_supply
subsystem as a battery, so that the device's Battery Strength can be
reported to usermode.
The battery appears in sysfs names
/sys/class/power_supply/hid-<UNIQ>-battery, and it is a child of the
battery-containing device, so it should be clear what it's the battery of.
Unfortunately on my current Fedora 16 system, while the battery does
appear in the UI, it is listed as a Laptop Battery with 0% charge (since
it ignores the "capacity" property of the battery and instead computes
it from the "energy*" fields, which we can't supply given the limited
information contained within the HID Report).
Still, this patch is the first step.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The mouse driver for Hyper-V is a HID compliant mouse driver.
Now that all relevant review comments have been addressed,
Jiri has agreed to merge this mouse driver into 3.3 hid.git.
This patch takes care of removing the mouse driver from the
staging area. Greg, if you can ack this patch, Jiri will proceed
with his merge.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch provides an option of having the lcla (link address)
in ESRAM instead of allocating it. The bool value (use_esram_lcla)
in the stedma40_platform_data if set to true, then the lcla
address would be taken from platform resources. Also, the
corresponding esram regulator is managed in the
suspend/resume functions.
Signed-off-by: Narayanan G <narayanan.gopalakrishnan@stericsson.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Sparse warns:
drivers/dma/timb_dma.c:168:17: warning: mixing different enum types
drivers/dma/timb_dma.c:168:17: int enum dma_transfer_direction versus
drivers/dma/timb_dma.c:168:17: int enum dma_data_direction
drivers/dma/timb_dma.c:172:32: warning: mixing different enum types
drivers/dma/timb_dma.c:172:32: int enum dma_transfer_direction versus
drivers/dma/timb_dma.c:172:32: int enum dma_data_direction
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
In S2R all DMA registers are reset by hardware and thus they are required to be
reprogrammed. The channels which aren't reprogrammed are channel configuration
and interrupt enable registers, which are currently programmed at chan_alloc
time.
This patch creates another routine to initialize a channel. It will try to
initialize channel on every dwc_dostart() call. If channel is already
initialised then it simply returns, otherwise it configures registers.
This routine will also initialize registers on wakeup from S2R, as we mark
channels as uninitialized on suspend.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
This patch converts the drivers in drivers/net/irda/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 8a0a9bd4db, this comment in mmap_rnd() does not
hold true as the value returned by get_random_int() will in fact be
different every single call. Remove the comment and simplify the code
back to its original desired form.
This reverts commit a5adc91a4b which is no longer necessary and
also fixes the sparc code that copied this same adjustment.
Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
During kdump stress testing I sometimes see the kdump kernel panic
with:
Interrupt 0x306 (real) is invalid, disabling it.
Kernel panic - not syncing: bad return code EOI - rc = -4, value=ff000306
Instead of panicing print the error message, dump the stack the first
time it happens and continue on. Add some more information to the
debug messages as well.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On a 64bit book3s machine I have an oops from a system reset that
claims the book3e CE bit was set:
MSR: 8000000000021032 <ME,CE,IR,DR> CR: 24004082 XER: 00000010
On a book3s machine system reset sets IBM bit 46 and 47 depending on
the power saving mode. Separate the definitions by type and for
completeness add the rest of the bits in.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In lieu of having multiple similiar lines, we can just have one
generic cpu-as line for CONFIG_ALTIVEC
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CPC925/CPC945 use special window to access host bridge functionality of
u3-ht. Provide a way to access this device.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
As described in the help text in the patch, this token restricts general
access to /dev/mem as a way of increasing the security. Specifically, access
to exclusive IOMEM and kernel RAM is denied unless CONFIG_STRICT_DEVMEM is
set to 'n'.
Implement the 'devmem_is_allowed()' interface for Powerpc. It will be
called from range_is_allowed() when userpsace attempts to access /dev/mem.
This patch is based on an earlier patch from Steve Best and with input from
Paul Mackerras and Scott Wood.
[BenH] Fixed a typo or two and removed the generic change which should
be submitted as a separate patch
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To perform PHY calibration and set a different EA value by chip ID,
Whenever the NIC chip power on, ie booting or resuming, we need to
force HW to calibrate PHY parameter again, and also set a proper EA
value which gather from experiment.
Those procedures help to reduce compatible issues(NIC is unable to link
up in some special case) in giga speed.
Signed-off-by: AriesLee <AriesLee@jmicron.com>
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The problem: Senders were overriding cwnd values picked during an undo
by calling tcp_moderate_cwnd() in tcp_try_to_open().
The fix: Don't moderate cwnd in tcp_try_to_open() if we're in
TCP_CA_Open, since doing so is generally unnecessary and specifically
would override a DSACK-based undo of a cwnd reduction made in fast
recovery.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously, SACK-enabled connections hung around in TCP_CA_Disorder
state while snd_una==high_seq, just waiting to accumulate DSACKs and
hopefully undo a cwnd reduction. This could and did lead to the
following unfortunate scenario: if some incoming ACKs advance snd_una
beyond high_seq then we were setting undo_marker to 0 and moving to
TCP_CA_Open, so if (due to reordering in the ACK return path) we
shortly thereafter received a DSACK then we were no longer able to
undo the cwnd reduction.
The change: Simplify the congestion avoidance state machine by
removing the behavior where SACK-enabled connections hung around in
the TCP_CA_Disorder state just waiting for DSACKs. Instead, when
snd_una advances to high_seq or beyond we typically move to
TCP_CA_Open immediately and allow an undo in either TCP_CA_Open or
TCP_CA_Disorder if we later receive enough DSACKs.
Other patches in this series will provide other changes that are
necessary to fully fix this problem.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
