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To: linux-kernel@vger.kernel.org
From: Jason Lunz <lunz@falooley.org>
Subject: Re: Strange write starvation on 2.6.17 (and other) kernels
Date: Tue, 15 Aug 2006 18:40:41 +0000 (UTC)
Organization: PBR Streetgang
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References: <44E0A69C.5030103@agh.edu.pl>
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szymans@agh.edu.pl said:
> I've encountered a strange problem - if an application is sequentially 
> writing a large file on a busy machine, a single write() of 64KB may 
> take even 30 seconds. But if I do fsync() after each write() the maximum 

If the sleeps are that long, and reproducible, then maybe you can find
the offending wait by using sysrq-t while the writer is blocked.

Jason