From: Yong Zhang <yong.zhang0@gmail.com>
To: Juri Lelli <juri.lelli@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: lock_stat &rq->lock/1 class name meaning
Date: Thu, 12 May 2011 18:57:56 +0800 [thread overview]
Message-ID: <20110512105756.GA3329@zhy> (raw)
In-Reply-To: <4DCAB8A2.8060605@linux.com>
On Wed, May 11, 2011 at 06:26:10PM +0200, Juri Lelli wrote:
> Hi,
> I'm trying to collect contention statistics through /proc/lock_stat
> about scheduler data structures.
>
> What I obtain if a do "cat /proc/lock_stat" is something like:
> ...
> &rq->lock: 13128 13128 0.43
> 190.53 103881.26 97454 3453404 0.00
> 401.11 13224683.11
> ---------
> &rq->lock 645 [<ffffffff8103bfc4>]
> task_rq_lock+0x43/0x75
> &rq->lock 297 [<ffffffff8104ba65>]
> try_to_wake_up+0x127/0x25a
> &rq->lock 360 [<ffffffff8103c4c5>]
> select_task_rq_fair+0x1f0/0x74a
> &rq->lock 428 [<ffffffff81045f98>]
> scheduler_tick+0x46/0x1fb
> ---------
> &rq->lock 77 [<ffffffff8103bfc4>]
> task_rq_lock+0x43/0x75
> &rq->lock 174 [<ffffffff8104ba65>]
> try_to_wake_up+0x127/0x25a
> &rq->lock 4715 [<ffffffff8103ed4b>]
> double_rq_lock+0x42/0x54
> &rq->lock 893 [<ffffffff81340524>] schedule+0x157/0x7b8
> .
> .
> .
> ...
> &rq->lock/1: 11526 11488 0.33
> 388.73 136294.31 21461 38404 0.00
> 37.93 109388.53
> -----------
> &rq->lock/1 11526 [<ffffffff8103ed58>]
> double_rq_lock+0x4f/0x54
> -----------
> &rq->lock/1 5645 [<ffffffff8103ed4b>]
> double_rq_lock+0x42/0x54
> &rq->lock/1 1224 [<ffffffff81340524>]
> schedule+0x157/0x7b8
> &rq->lock/1 4336 [<ffffffff8103ed58>]
> double_rq_lock+0x4f/0x54
> &rq->lock/1 181 [<ffffffff8104ba65>]
> try_to_wake_up+0x127/0x25a
>
> I guess the first one is about the per-rq (per-CPU) spinlock, but
> what about the second? What the "/1" stands for?
It is also rq but it's subclass is 1.
Take a look at raw_spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
in _double_lock_balance()
> Since every rq has a different spinlock, does &rq->lock group
> numbers from all the runqueues?
Yup.
Thanks,
Yong
>
> Thanks a lot,
> Juri
> --
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next prev parent reply other threads:[~2011-05-12 10:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-11 16:26 lock_stat &rq->lock/1 class name meaning Juri Lelli
2011-05-12 10:57 ` Yong Zhang [this message]
2011-05-12 12:11 ` Juri Lelli
2011-05-12 12:26 ` Yong Zhang
2011-05-12 14:22 ` Américo Wang
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