From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
linux-scsi@vger.kernel.org, Lukasz Dorau <lukasz.dorau@intel.com>,
James Bottomley <JBottomley@parallels.com>,
Andrzej Jakowski <andrzej.jakowski@intel.com>
Subject: Re: [RFC PATCH] kick ksoftirqd more often to please soft lockup detector
Date: Wed, 29 Feb 2012 10:17:03 +0100 [thread overview]
Message-ID: <1330507023.11248.113.camel@twins> (raw)
In-Reply-To: <CABE8wwsmWqDddMqgQ6HvMPkbK+Vu7G7GOY-VO_Tru2JV2NUUcw@mail.gmail.com>
On Tue, 2012-02-28 at 14:16 -0800, Dan Williams wrote:
> Looks like everyone is guilty:
>
> [ 422.765336] softirq took longer than 1/4 tick: 3 NET_RX ffffffff813f0aa0
> ...
> [ 423.971878] softirq took longer than 1/4 tick: 4 BLOCK ffffffff812519c8
> [ 423.985093] softirq took longer than 1/4 tick: 6 TASKLET ffffffff8103422e
> [ 423.993157] softirq took longer than 1/4 tick: 7 SCHED ffffffff8105e2e1
> [ 424.001018] softirq took longer than 1/4 tick: 9 RCU ffffffff810a0fed
> [ 424.008691] softirq loop took longer than 1/2 tick need_resched:
/me kicks himself for not printing the actual duration.. :-)
> As expected whenever that 1/2 tick message gets emitted the softirq
> handler is almost running in a need_resched() context.
Yeah.. that's quite expected.
> So is it a good idea to get more aggressive about scheduling ksoftrrqd?
Nah, moving away from softirq more like. I'll put moving the
load-balancer into a kthread on the todo list. And it looks like
everybody else should move to kthreads too.
next prev parent reply other threads:[~2012-02-29 9:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-27 20:38 [RFC PATCH] kick ksoftirqd more often to please soft lockup detector Dan Williams
2012-02-28 8:35 ` Yong Zhang
2012-02-28 9:48 ` Peter Zijlstra
2012-02-28 16:48 ` Dan Williams
2012-02-28 21:41 ` Thomas Gleixner
2012-02-28 22:16 ` Dan Williams
2012-02-28 22:25 ` Dan Williams
2012-02-29 9:17 ` Peter Zijlstra [this message]
2012-02-29 19:49 ` Dan Williams
2012-03-03 8:39 ` Paul E. McKenney
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