From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <jaxboe@fusionio.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, Tejun Heo <tj@kernel.org>
Subject: Re: [RFC][PATCH 1/3] sched, block: Move unplug
Date: Wed, 22 Jun 2011 16:38:01 +0200 [thread overview]
Message-ID: <1308753481.1022.27.camel@twins> (raw)
In-Reply-To: <alpine.LFD.2.02.1106221628560.11814@ionos>
On Wed, 2011-06-22 at 16:30 +0200, Thomas Gleixner wrote:
> > It is supposedly a real problem, not just an inkling. It's not about
> > recursing indefinitely, the plug is fairly bounded. But the IO dispatch
> > path can be pretty deep, and if you hit that deep inside the reclaim or
> > file system write path, then you get dangerously close. Dave Chinner
> > posted some numbers in the 2.6.39-rc1 time frame showing how close we
> > got.
>
> Fair enough.
> Ok. So we move it out and keep the from_scheduler flag so that code
> does not go down the IO path from there.
Won't punting the plug to a worker thread wreck all kinds of io
accounting due to the wrong task doing the actual io submission?
next prev parent reply other threads:[~2011-06-22 14:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-21 23:34 [RFC][PATCH 0/3] Move WQ,unplug scheduler hooks Peter Zijlstra
2011-06-21 23:34 ` [RFC][PATCH 1/3] sched, block: Move unplug Peter Zijlstra
2011-06-22 7:01 ` Jens Axboe
2011-06-22 13:53 ` Thomas Gleixner
2011-06-22 14:01 ` Jens Axboe
2011-06-22 14:30 ` Thomas Gleixner
2011-06-22 14:38 ` Peter Zijlstra [this message]
2011-06-22 15:08 ` Vivek Goyal
2011-06-22 16:04 ` Jens Axboe
2011-06-21 23:34 ` [RFC][PATCH 2/3] sched, workqueue: Move WQ-sleeper wakeup Peter Zijlstra
2011-06-22 9:24 ` Tejun Heo
2011-06-22 9:27 ` Peter Zijlstra
2011-06-22 9:37 ` Tejun Heo
2011-06-22 13:47 ` Thomas Gleixner
2011-06-21 23:34 ` [RFC][PATCH 3/3] block: Break long IRQ disabled region Peter Zijlstra
2011-06-22 7:03 ` Jens Axboe
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