From: Andrew Morton <akpm@zip.com.au>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alexander Moibenko <moibenko@fnal.gov>, linux-kernel@vger.kernel.org
Subject: Re: fsync delays for a long time.
Date: Thu, 14 Feb 2002 13:20:57 -0800 [thread overview]
Message-ID: <3C6C2A39.38ED19B1@zip.com.au> (raw)
In-Reply-To: <3C6C2342.5044B738@zip.com.au> from "Andrew Morton" at Feb 14, 2002 12:51:14 PM <E16bT7y-00017B-00@the-village.bc.nu>
Alan Cox wrote:
>
> > > fsync on a very large file is very slow on the 2.2 kernels
> >
> > This could very well be due to request allocation starvation.
> > fsync is sleeping in __get_request_wait() while bonnie keeps
> > on stealing all the requests.
>
> That may amplify it but in the 2.2 case fsync on any sensible sized file
> is already horribly performing. It hits databases like solid quite badly
I'm surprised. ext2's fsync in 2.2 is in fact quite optimal: a single
pass across the block tree, in probable-LBA-order. No livelock potential
there. Optimal. Note that it implements "only sync the stuff which was
dirty on entry" semantics.
But msync() is a different kettle of fish. It calls file_fsync(), which
syncs the entire device, livelockably. Are you sure `solid' is not
using msync?
-
next prev parent reply other threads:[~2002-02-14 21:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-14 16:03 fsync delays for a long time Alexander Moibenko
2002-02-14 17:39 ` Alan Cox
2002-02-14 20:51 ` Andrew Morton
2002-02-14 21:09 ` Alan Cox
2002-02-14 21:12 ` Alexander Moibenko
2002-02-14 21:37 ` Alan Cox
2002-02-14 21:26 ` Alexander Moibenko
2002-02-14 21:41 ` Andrew Morton
2002-02-14 22:18 ` Alexander Moibenko
2002-02-14 21:20 ` Andrew Morton [this message]
2002-02-14 21:38 ` Alan Cox
2002-02-15 16:48 ` Stephen C. Tweedie
2002-02-15 17:24 ` Simon Kirby
2002-02-15 19:07 ` Andrew Morton
2002-02-15 19:21 ` Simon Kirby
2002-02-17 12:47 ` Bill Davidsen
2002-02-17 16:45 ` Simon Kirby
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