* [RESEND PATCH] Documentation: statistics about nested locks
@ 2011-05-19 10:53 Juri Lelli
2011-05-19 11:46 ` Peter Zijlstra
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Juri Lelli @ 2011-05-19 10:53 UTC (permalink / raw)
To: linux-kernel; +Cc: Peter Zijlstra, Ingo Molnar, Yong Zhang, trivial
Explain what the trailing "/1" on some lock class names of lock_stat output
means.
Cc: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
---
Documentation/lockstat.txt | 36 ++++++++++++++++++++++++++++++++++--
1 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt
index 65f4c79..75eeb65 100644
--- a/Documentation/lockstat.txt
+++ b/Documentation/lockstat.txt
@@ -12,8 +12,9 @@ Because things like lock contention can severely impact performance.
- HOW
Lockdep already has hooks in the lock functions and maps lock instances to
-lock classes. We build on that. The graph below shows the relation between
-the lock functions and the various hooks therein.
+lock classes. We build on that (see Documentation/lockdep-design.txt).
+The graph below shows the relation between the lock functions and the various
+hooks therein.
__acquire
|
@@ -128,6 +129,37 @@ points are the points we're contending with.
The integer part of the time values is in us.
+Dealing with nested locks, subclasses may appear:
+
+32...............................................................................................................................................................................................
+33
+34 &rq->lock: 13128 13128 0.43 190.53 103881.26 97454 3453404 0.00 401.11 13224683.11
+35 ---------
+36 &rq->lock 645 [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+37 &rq->lock 297 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+38 &rq->lock 360 [<ffffffff8103c4c5>] select_task_rq_fair+0x1f0/0x74a
+39 &rq->lock 428 [<ffffffff81045f98>] scheduler_tick+0x46/0x1fb
+40 ---------
+41 &rq->lock 77 [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+42 &rq->lock 174 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+43 &rq->lock 4715 [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+44 &rq->lock 893 [<ffffffff81340524>] schedule+0x157/0x7b8
+45
+46...............................................................................................................................................................................................
+47
+48 &rq->lock/1: 11526 11488 0.33 388.73 136294.31 21461 38404 0.00 37.93 109388.53
+49 -----------
+50 &rq->lock/1 11526 [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+51 -----------
+52 &rq->lock/1 5645 [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+53 &rq->lock/1 1224 [<ffffffff81340524>] schedule+0x157/0x7b8
+54 &rq->lock/1 4336 [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+55 &rq->lock/1 181 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+
+Line 48 shows statistics for the second subclass (/1) of &rq->lock class
+(subclass starts from 0), since in this case, as line 50 suggests,
+double_rq_lock actually acquires a nested lock of two spinlocks.
+
View the top contending locks:
# grep : /proc/lock_stat | head
--
1.7.4.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RESEND PATCH] Documentation: statistics about nested locks
2011-05-19 10:53 [RESEND PATCH] Documentation: statistics about nested locks Juri Lelli
@ 2011-05-19 11:46 ` Peter Zijlstra
2011-05-20 1:20 ` Yong Zhang
2011-05-28 16:36 ` [tip:core/urgent] Documentation: Add " tip-bot for Juri Lelli
2 siblings, 0 replies; 4+ messages in thread
From: Peter Zijlstra @ 2011-05-19 11:46 UTC (permalink / raw)
To: Juri Lelli; +Cc: linux-kernel, Ingo Molnar, Yong Zhang, trivial
On Thu, 2011-05-19 at 12:53 +0200, Juri Lelli wrote:
> Explain what the trailing "/1" on some lock class names of lock_stat output
> means.
great, this applies without problems, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RESEND PATCH] Documentation: statistics about nested locks
2011-05-19 10:53 [RESEND PATCH] Documentation: statistics about nested locks Juri Lelli
2011-05-19 11:46 ` Peter Zijlstra
@ 2011-05-20 1:20 ` Yong Zhang
2011-05-28 16:36 ` [tip:core/urgent] Documentation: Add " tip-bot for Juri Lelli
2 siblings, 0 replies; 4+ messages in thread
From: Yong Zhang @ 2011-05-20 1:20 UTC (permalink / raw)
To: Juri Lelli; +Cc: linux-kernel, Peter Zijlstra, Ingo Molnar, trivial
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=UTF-8, Size: 4841 bytes --]
On Thu, May 19, 2011 at 6:53 PM, Juri Lelli <juri.lelli@gmail.com> wrote:
> Explain what the trailing "/1" on some lock class names of lock_stat output
> means.
>
> Cc: Yong Zhang <yong.zhang0@gmail.com>
> Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
>
Looks good.
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
> ---
> Â Documentation/lockstat.txt | Â 36 ++++++++++++++++++++++++++++++++++--
> Â 1 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt
> index 65f4c79..75eeb65 100644
> --- a/Documentation/lockstat.txt
> +++ b/Documentation/lockstat.txt
> @@ -12,8 +12,9 @@ Because things like lock contention can severely impact performance.
> Â - HOW
>
> Â Lockdep already has hooks in the lock functions and maps lock instances to
> -lock classes. We build on that. The graph below shows the relation between
> -the lock functions and the various hooks therein.
> +lock classes. We build on that (see Documentation/lockdep-design.txt).
> +The graph below shows the relation between the lock functions and the various
> +hooks therein.
>
> Â Â Â Â __acquire
> Â Â Â Â Â Â |
> @@ -128,6 +129,37 @@ points are the points we're contending with.
>
> Â The integer part of the time values is in us.
>
> +Dealing with nested locks, subclasses may appear:
> +
> +32...............................................................................................................................................................................................
> +33
> +34 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock: Â Â Â Â 13128 Â Â Â Â Â 13128 Â Â Â Â Â 0.43 Â Â Â Â 190.53 Â Â Â 103881.26 Â Â Â Â Â 97454 Â Â Â Â 3453404 Â Â Â Â Â 0.00 Â Â Â Â 401.11 Â Â 13224683.11
> +35 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ---------
> +36                &rq->lock       645      [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
> +37                &rq->lock       297      [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
> +38                &rq->lock       360      [<ffffffff8103c4c5>] select_task_rq_fair+0x1f0/0x74a
> +39                &rq->lock       428      [<ffffffff81045f98>] scheduler_tick+0x46/0x1fb
> +40 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ---------
> +41                &rq->lock       77      [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
> +42                &rq->lock       174      [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
> +43                &rq->lock      4715      [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
> +44                &rq->lock       893      [<ffffffff81340524>] schedule+0x157/0x7b8
> +45
> +46...............................................................................................................................................................................................
> +47
> +48 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1: Â Â Â Â 11526 Â Â Â Â Â 11488 Â Â Â Â Â 0.33 Â Â Â Â 388.73 Â Â Â 136294.31 Â Â Â Â Â 21461 Â Â Â Â Â 38404 Â Â Â Â Â 0.00 Â Â Â Â Â 37.93 Â Â Â 109388.53
> +49 Â Â Â Â Â Â Â Â Â Â Â Â Â Â -----------
> +50 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1 Â Â Â Â Â 11526 Â Â Â Â Â [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
> +51 Â Â Â Â Â Â Â Â Â Â Â Â Â Â -----------
> +52 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1 Â Â Â Â Â 5645 Â Â Â Â Â [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
> +53 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1 Â Â Â Â Â 1224 Â Â Â Â Â [<ffffffff81340524>] schedule+0x157/0x7b8
> +54 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1 Â Â Â Â Â 4336 Â Â Â Â Â [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
> +55 Â Â Â Â Â Â Â Â Â Â Â Â Â Â &rq->lock/1 Â Â Â Â Â Â 181 Â Â Â Â Â [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
> +
> +Line 48 shows statistics for the second subclass (/1) of &rq->lock class
> +(subclass starts from 0), since in this case, as line 50 suggests,
> +double_rq_lock actually acquires a nested lock of two spinlocks.
> +
> Â View the top contending locks:
>
> Â # grep : /proc/lock_stat | head
> --
> 1.7.4.1
>
--
Only stand for myself
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:core/urgent] Documentation: Add statistics about nested locks
2011-05-19 10:53 [RESEND PATCH] Documentation: statistics about nested locks Juri Lelli
2011-05-19 11:46 ` Peter Zijlstra
2011-05-20 1:20 ` Yong Zhang
@ 2011-05-28 16:36 ` tip-bot for Juri Lelli
2 siblings, 0 replies; 4+ messages in thread
From: tip-bot for Juri Lelli @ 2011-05-28 16:36 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, a.p.zijlstra, tglx, yong.zhang0,
juri.lelli, mingo
Commit-ID: f62508f68d04adefc4cf9b0177ba02c8818b3eec
Gitweb: http://git.kernel.org/tip/f62508f68d04adefc4cf9b0177ba02c8818b3eec
Author: Juri Lelli <juri.lelli@gmail.com>
AuthorDate: Thu, 19 May 2011 12:53:53 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 28 May 2011 17:03:29 +0200
Documentation: Add statistics about nested locks
Explain what the trailing "/1" on some lock class names of
lock_stat output means.
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4DD4F6C1.5090701@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
Documentation/lockstat.txt | 36 ++++++++++++++++++++++++++++++++++--
1 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt
index 9c0a80d..cef00d4 100644
--- a/Documentation/lockstat.txt
+++ b/Documentation/lockstat.txt
@@ -12,8 +12,9 @@ Because things like lock contention can severely impact performance.
- HOW
Lockdep already has hooks in the lock functions and maps lock instances to
-lock classes. We build on that. The graph below shows the relation between
-the lock functions and the various hooks therein.
+lock classes. We build on that (see Documentation/lockdep-design.txt).
+The graph below shows the relation between the lock functions and the various
+hooks therein.
__acquire
|
@@ -128,6 +129,37 @@ points are the points we're contending with.
The integer part of the time values is in us.
+Dealing with nested locks, subclasses may appear:
+
+32...............................................................................................................................................................................................
+33
+34 &rq->lock: 13128 13128 0.43 190.53 103881.26 97454 3453404 0.00 401.11 13224683.11
+35 ---------
+36 &rq->lock 645 [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+37 &rq->lock 297 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+38 &rq->lock 360 [<ffffffff8103c4c5>] select_task_rq_fair+0x1f0/0x74a
+39 &rq->lock 428 [<ffffffff81045f98>] scheduler_tick+0x46/0x1fb
+40 ---------
+41 &rq->lock 77 [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+42 &rq->lock 174 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+43 &rq->lock 4715 [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+44 &rq->lock 893 [<ffffffff81340524>] schedule+0x157/0x7b8
+45
+46...............................................................................................................................................................................................
+47
+48 &rq->lock/1: 11526 11488 0.33 388.73 136294.31 21461 38404 0.00 37.93 109388.53
+49 -----------
+50 &rq->lock/1 11526 [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+51 -----------
+52 &rq->lock/1 5645 [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+53 &rq->lock/1 1224 [<ffffffff81340524>] schedule+0x157/0x7b8
+54 &rq->lock/1 4336 [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+55 &rq->lock/1 181 [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+
+Line 48 shows statistics for the second subclass (/1) of &rq->lock class
+(subclass starts from 0), since in this case, as line 50 suggests,
+double_rq_lock actually acquires a nested lock of two spinlocks.
+
View the top contending locks:
# grep : /proc/lock_stat | head
^ permalink raw reply related [flat|nested] 4+ messages in thread
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2011-05-19 10:53 [RESEND PATCH] Documentation: statistics about nested locks Juri Lelli
2011-05-19 11:46 ` Peter Zijlstra
2011-05-20 1:20 ` Yong Zhang
2011-05-28 16:36 ` [tip:core/urgent] Documentation: Add " tip-bot for Juri Lelli
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