From: Timo Sirainen <tss@iki.fi>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ray Lee <ray-lk@madrabbit.org>, linux-kernel@vger.kernel.org
Subject: Re: SMP read() stopping at memory page boundaries
Date: Wed, 20 Jun 2007 20:48:20 +0300 [thread overview]
Message-ID: <1182361700.3768.107.camel@hurina> (raw)
In-Reply-To: <20070620180500.6e2d600a@the-village.bc.nu>
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On Wed, 2007-06-20 at 18:05 +0100, Alan Cox wrote:
> > I thought this wouldn't happen when reading from local filesystems.
> > Anyway, my real program was doing that, and it was still seeing partial
> > data. But looks like I can't reproduce it in my test program with two
> > pread()s, so I'll have to do some more debugging.
Found the problem in my code. A buggy program, buggy test program and a
buggy brain while debugging doesn't seem to give the best results. :)
> It will occur if you are reading as someone else changes the file size.
> Use file locking, it exists for a reason ;)
Annoying extra overhead. Especially with NFS, when nowadays you can't
even use flock() to create local locks..
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next prev parent reply other threads:[~2007-06-20 17:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-20 14:52 SMP read() stopping at memory page boundaries Timo Sirainen
2007-06-20 15:48 ` Timo Sirainen
2007-06-20 16:22 ` Ray Lee
2007-06-20 16:57 ` Timo Sirainen
2007-06-20 17:05 ` Alan Cox
2007-06-20 17:48 ` Timo Sirainen [this message]
2007-06-20 23:22 ` Jiri Kosina
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