From: Chris Mason <chris.mason@Oracle.COM>
To: Sanjoy Mahajan <sanjoy@olin.edu>
Cc: Ingo Molnar <mingo@elte.hu>, Pekka Enberg <penberg@kernel.org>,
Aidar Kultayev <the.aidar@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>,
Peter.Zijl@MIT.EDU
Subject: Re: 2.6.36 io bring the system to its knees
Date: Tue, 2 Nov 2010 09:12:39 -0400 [thread overview]
Message-ID: <20101102131239.GA8680@think> (raw)
In-Reply-To: <E1PDFKe-0005sq-2D@approx.mit.edu>
On Tue, Nov 02, 2010 at 07:47:15AM -0400, Sanjoy Mahajan wrote:
> Chris Mason <chris.mason@oracle.com> wrote:
>
> > > This has the appearance of some really bad IO or VM latency
> > > problem. Unfixed and present in stable kernel versions going from
> > > years ago all the way to v2.6.36.
> >
> > Hmmm, the workload you're describing here has two special parts.
> > First it dramatically overloads the disk, and then it has guis doing
> > things waiting for the disk.
>
> I think I see this same issue every few days when I back up my hard
> drive to a USB hard drive using rsync. While the backup is running, the
> interactive response is bad. A reproducible measurement of the badness
> is starting an rxvt with F8 (bound to "rxvt &" in my .twmrc). Often it
> takes 8 seconds for the window to appear (as it just did about 2 minutes
> ago)! (Starting a subsequent rxvt is quick.)
So this sounds like the backup is just thrashing your cache. Latencies
starting an app are less surprising than latencies where a running app
doesn't respond at all.
Does rsync have the option to do an fadvise DONTNEED?
-chris
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next prev parent reply other threads:[~2010-11-02 13:14 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AANLkTimt7wzR9RwGWbvhiOmot_zzayfCfSh_-v6yvuAP@mail.gmail.com>
[not found] ` <AANLkTikRKVBzO=ruy=JDmBF28NiUdJmAqb4-1VhK0QBX@mail.gmail.com>
[not found] ` <AANLkTinzJ9a+9w7G5X0uZpX2o-L8E6XW98VFKoF1R_-S@mail.gmail.com>
2010-10-28 6:09 ` 2.6.36 io bring the system to its knees Aidar Kultayev
2010-10-28 6:32 ` Pekka Enberg
2010-10-28 9:00 ` Ingo Molnar
2010-10-28 9:34 ` Pekka Enberg
2010-10-28 11:16 ` Pekka Enberg
2010-10-28 11:33 ` Aidar Kultayev
2010-10-28 11:48 ` Pekka Enberg
2010-10-28 12:18 ` Aidar Kultayev
2010-10-28 13:46 ` Christoph Hellwig
2010-10-28 13:54 ` Ingo Molnar
2010-10-28 13:30 ` Ingo Molnar
2010-10-28 13:47 ` Christoph Hellwig
2010-10-28 13:50 ` Ingo Molnar
2010-10-28 17:01 ` Chris Mason
2010-10-28 17:57 ` Pekka Enberg
2010-10-29 14:52 ` Ted Ts'o
2010-10-29 15:33 ` Aidar Kultayev
2010-10-30 9:14 ` Ingo Molnar
2010-10-30 13:02 ` Aidar Kultayev
2010-10-30 19:06 ` Chris Mason
2010-10-31 2:31 ` Ted Ts'o
2010-10-31 17:49 ` Corrado Zoccolo
2010-11-02 3:10 ` Shaohua Li
2010-11-02 11:47 ` Sanjoy Mahajan
2010-11-02 13:12 ` Chris Mason [this message]
2010-11-04 16:05 ` Sanjoy Mahajan
2010-11-04 23:35 ` Steven Barrett
2010-11-04 23:44 ` Jesper Juhl
2010-11-04 23:48 ` Jesper Juhl
2010-11-05 1:43 ` Dave Chinner
2010-11-05 12:48 ` Sanjoy Mahajan
2010-11-06 14:10 ` dave b
2010-11-06 15:12 ` Dave Chinner
2010-11-07 6:06 ` dave b
2010-11-07 12:08 ` Jens Axboe
2010-11-07 15:50 ` Linus Torvalds
2010-11-10 1:32 ` Dave Chinner
2010-11-10 2:01 ` dave b
2010-11-10 8:08 ` Evgeniy Ivanov
2010-11-10 8:24 ` Dave Chinner
2010-11-10 14:22 ` Pavel Machek
2010-11-10 14:20 ` Pavel Machek
2010-11-10 14:27 ` Ingo Molnar
2010-11-10 14:55 ` Christoph Hellwig
2010-11-10 19:09 ` Pavel Machek
2010-11-10 14:33 ` Theodore Tso
2010-11-10 14:57 ` Christoph Hellwig
2010-11-10 15:00 ` Chris Mason
2010-11-10 23:36 ` Dave Chinner
2010-11-10 15:59 ` Linus Torvalds
2010-11-10 16:46 ` Alexey Dobriyan
2010-11-10 16:55 ` Linus Torvalds
2010-11-10 17:10 ` Alexey Dobriyan
2010-11-10 18:55 ` Mark Lord
2010-11-10 18:27 ` Mike Galbraith
2010-11-10 23:43 ` Dave Chinner
2010-11-06 19:10 ` Arjan van de Ven
2010-11-07 17:16 ` Jesper Juhl
2010-11-09 19:47 ` Evgeniy Ivanov
2010-11-09 20:20 ` Christoph Hellwig
2010-11-09 21:00 ` Chris Mason
2010-10-31 1:22 ` Wu Fengguang
2010-10-31 1:51 ` Wu Fengguang
2010-11-01 1:09 ` Dimitrios Apostolou
2010-11-02 1:20 ` Wu Fengguang
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