From: Ingo Molnar <mingo@elte.hu>
To: Lee Revell <rlrevell@joe-job.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
"Paul E. McKenney" <paulmck@us.ibm.com>
Subject: Re: 2.6.14-rt22 (and mainline) excessive latency
Date: Tue, 20 Dec 2005 05:24:42 +0100 [thread overview]
Message-ID: <20051220042442.GA32039@elte.hu> (raw)
In-Reply-To: <1135039244.28649.41.camel@mindpipe>
* Lee Revell <rlrevell@joe-job.com> wrote:
> I captured this 3+ ms latency trace when killing a process with a few
> thousand threads. Can a cond_resched be added to this code path?
> bash-17992 0.n.1 29us : eligible_child (do_wait)
>
> [ 3000+ of these deleted ]
>
> bash-17992 0.n.1 3296us : eligible_child (do_wait)
Atomicity of signal delivery is pretty much a must, so i'm not sure this
particular latency can be fixed, short of running PREEMPT_RT. Paul E.
McKenney is doing some excellent stuff by RCU-ifying the task lookup and
signal code, but i'm not sure whether it could cover do_wait().
Ingo
next prev parent reply other threads:[~2005-12-20 4:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-20 0:40 2.6.14-rt22 (and mainline) excessive latency Lee Revell
2005-12-20 4:24 ` Ingo Molnar [this message]
2005-12-21 1:47 ` Paul E. McKenney
2005-12-21 3:32 ` Lee Revell
2005-12-21 13:36 ` Paul E. McKenney
2005-12-21 19:54 ` Lee Revell
2005-12-23 4:07 ` Paul E. McKenney
2005-12-23 4:22 ` Lee Revell
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