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linux/lib/percpu_ida.c

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idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
sched/headers: Prepare to remove the <linux/gfp.h> include from <linux/sched.h> <linux/topology.h> is still needed - also update other headers and .c files that depend on sched.h including gfp.h (and its sub-headers) for them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-02 20:56:33 +01:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-02 19:15:33 +01:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: fix a live lock steal_tags only happens when free tags is more than half of the total tags. This is too strict and can cause live lock. I found that if one cpu has free tags, but other cpu can't steal (thread is bound to specific cpus), threads which want to allocate tags are always sleeping. I found this when I run next patch, but this could happen without it I think. I did performance test too with null_blk. Two cases (each cpu has enough percpu tags, or total tags are limited), no performance changes were observed. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-12-31 11:38:27 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: fix a live lock steal_tags only happens when free tags is more than half of the total tags. This is too strict and can cause live lock. I found that if one cpu has free tags, but other cpu can't steal (thread is bound to specific cpus), threads which want to allocate tags are always sleeping. I found this when I run next patch, but this could happen without it I think. I did performance test too with null_blk. Two cases (each cpu has enough percpu tags, or total tags are limited), no performance changes were observed. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-12-31 11:38:27 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Removing unused arguement from alloc_local_tag Removing unused struct percpu_ida *pool from arguements of alloc_local_tag, changed it's one use in percpu_ida.c (nab: Fixed reference of idr.c -> percpu_ida.c) Signed-Off-By: Nick Swenson <nks@daterainc.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-10-02 17:55:45 -07:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask This patch changes percpu_ida_alloc() + callers to accept task state bitmask for prepare_to_wait() for code like target/iscsi that needs it for interruptible sleep, that is provided in a subsequent patch. It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, and is forced to return a negative value when no tags are available. v2 changes: - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes - Drop signal_pending_state() call v3 changes: - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING (PeterZ) Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-19 08:26:37 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
iscsi-target: Fix connection reset hang with percpu_ida_alloc This patch addresses a bug where connection reset would hang indefinately once percpu_ida_alloc() was starved for tags, due to the fact that it always assumed uninterruptible sleep mode. So now make percpu_ida_alloc() check for signal_pending_state() for making interruptible sleep optional, and convert iscsit_allocate_cmd() to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for GFP_ATOMIC. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-20 03:36:24 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM __GFP_WAIT was used to signal that the caller was in atomic context and could not sleep. Now it is possible to distinguish between true atomic context and callers that are not willing to sleep. The latter should clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing __GFP_WAIT behaves differently, there is a risk that people will clear the wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly indicate what it does -- setting it allows all reclaim activity, clearing them prevents it. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 16:28:28 -08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
iscsi-target: Fix connection reset hang with percpu_ida_alloc This patch addresses a bug where connection reset would hang indefinately once percpu_ida_alloc() was starved for tags, due to the fact that it always assumed uninterruptible sleep mode. So now make percpu_ida_alloc() check for signal_pending_state() for making interruptible sleep optional, and convert iscsit_allocate_cmd() to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for GFP_ATOMIC. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-20 03:36:24 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask This patch changes percpu_ida_alloc() + callers to accept task state bitmask for prepare_to_wait() for code like target/iscsi that needs it for interruptible sleep, that is provided in a subsequent patch. It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, and is forced to return a negative value when no tags are available. v2 changes: - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes - Drop signal_pending_state() call v3 changes: - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING (PeterZ) Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-19 08:26:37 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Removing unused arguement from alloc_local_tag Removing unused struct percpu_ida *pool from arguements of alloc_local_tag, changed it's one use in percpu_ida.c (nab: Fixed reference of idr.c -> percpu_ida.c) Signed-Off-By: Nick Swenson <nks@daterainc.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-10-02 17:55:45 -07:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask This patch changes percpu_ida_alloc() + callers to accept task state bitmask for prepare_to_wait() for code like target/iscsi that needs it for interruptible sleep, that is provided in a subsequent patch. It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, and is forced to return a negative value when no tags are available. v2 changes: - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes - Drop signal_pending_state() call v3 changes: - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING (PeterZ) Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-19 08:26:37 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask This patch changes percpu_ida_alloc() + callers to accept task state bitmask for prepare_to_wait() for code like target/iscsi that needs it for interruptible sleep, that is provided in a subsequent patch. It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, and is forced to return a negative value when no tags are available. v2 changes: - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes - Drop signal_pending_state() call v3 changes: - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING (PeterZ) Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-19 08:26:37 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
iscsi-target: Fix connection reset hang with percpu_ida_alloc This patch addresses a bug where connection reset would hang indefinately once percpu_ida_alloc() was starved for tags, due to the fact that it always assumed uninterruptible sleep mode. So now make percpu_ida_alloc() check for signal_pending_state() for making interruptible sleep optional, and convert iscsit_allocate_cmd() to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for GFP_ATOMIC. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-20 03:36:24 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask This patch changes percpu_ida_alloc() + callers to accept task state bitmask for prepare_to_wait() for code like target/iscsi that needs it for interruptible sleep, that is provided in a subsequent patch. It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep waiting for a new tag, or TASK_RUNNING when the caller cannot sleep, and is forced to return a negative value when no tags are available. v2 changes: - Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes - Drop signal_pending_state() call v3 changes: - Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING (PeterZ) Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: <stable@vger.kernel.org> #3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-01-19 08:26:37 +00:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
idr: Percpu ida Percpu frontend for allocating ids. With percpu allocation (that works), it's impossible to guarantee it will always be possible to allocate all nr_tags - typically, some will be stuck on a remote percpu freelist where the current job can't get to them. We do guarantee that it will always be possible to allocate at least (nr_tags / 2) tags - this is done by keeping track of which and how many cpus have tags on their percpu freelists. On allocation failure if enough cpus have tags that there could potentially be (nr_tags / 2) tags stuck on remote percpu freelists, we then pick a remote cpu at random to steal from. Note that there's no cpu hotplug notifier - we don't care, because steal_tags() will eventually get the down cpu's tags. We _could_ satisfy more allocations if we had a notifier - but we'll still meet our guarantees and it's absolutely not a correctness issue, so I don't think it's worth the extra code. From akpm: "It looks OK to me (that's as close as I get to an ack :)) v6 changes: - Add #include <linux/cpumask.h> to include/linux/percpu_ida.h to make alpha/arc builds happy (Fengguang) - Move second (cpu >= nr_cpu_ids) check inside of first check scope in steal_tags() (akpm + nab) v5 changes: - Change percpu_ida->cpus_have_tags to cpumask_t (kmo + akpm) - Add comment for percpu_ida_cpu->lock + ->nr_free (kmo + akpm) - Convert steal_tags() to use cpumask_weight() + cpumask_next() + cpumask_first() + cpumask_clear_cpu() (kmo + akpm) - Add comment for alloc_global_tags() (kmo + akpm) - Convert percpu_ida_alloc() to use cpumask_set_cpu() (kmo + akpm) - Convert percpu_ida_free() to use cpumask_set_cpu() (kmo + akpm) - Drop percpu_ida->cpus_have_tags allocation in percpu_ida_init() (kmo + akpm) - Drop percpu_ida->cpus_have_tags kfree in percpu_ida_destroy() (kmo + akpm) - Add comment for percpu_ida_alloc @ gfp (kmo + akpm) - Move to percpu_ida.c + percpu_ida.h (kmo + akpm + nab) v4 changes: - Fix tags.c reference in percpu_ida_init (akpm) Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-08-16 22:04:37 +00:00
percpu_ida: make percpu_ida percpu size/batch configurable Make percpu_ida percpu size/batch configurable. The block-mq-tag will use it. After block-mq uses percpu_ida to manage tags, performance is improved. My test is done in a 2 sockets machine, 12 process cross the 2 sockets. So if there is lock contention or ipi, should be stressed heavily. Testing is done for null-blk. hw_queue_depth nopatch iops patch iops 64 ~800k/s ~1470k/s 2048 ~4470k/s ~4340k/s Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:01 +08:00
percpu_ida: add percpu_ida_for_each_free Add a new API to iterate free ids. blk-mq-tag will use it. Note, this doesn't guarantee to iterate all free ids restrictly. Caller should be aware of this. blk-mq uses it to do sanity check for request timedout, so can tolerate the limitation. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:02 +08:00
percpu_ida: add an API to return free tags Add an API to return free tags, blk-mq-tag will use it. Note, this just returns a snapshot of free tags number. blk-mq-tag has two usages of it. One is for info output for diagnosis. The other is to quickly check if there are free tags for request dispatch checking. Neither requires very precise. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-15 09:05:03 +08:00