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From: Duncan Sands <baldrick@wanadoo.fr>
To: zlatko.calusic@iskon.hr, Alessandro Suardi <alessandro.suardi@oracle.com>
Subject: Re: [PATCH] Re: Shared memory shmat/dt not working well in 2.5.x
Date: Tue, 8 Oct 2002 13:38:50 +0200
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Cc: Hugh Dickins <hugh@veritas.com>, Andrew Morton <akpm@digeo.com>,
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> I also observed that other application I use occasionally - LXR (Linux
> source cross referencing tool) - takes much longer to generate xref
> database (which is in Berkeley DB files). It works in three passes,
> where the last one, when it dumps symbols into DB, is interesting. In
> 2.4 it finishes quickly (it uses 100% CPU, then occasionally syncs the
> databases - heavy write traffic for a second - then continues), but
> 2.5 has problems with it (it stucks writing to disk all the time, CPU
> usage is minimal and process progresses very slowly). Andrew, if
> you're interested I can send you some numbers to describe the case
> better.

Hmmm, are you using ext3?  Changes to the meaning of yield sometimes
make fsync go very slowly.  This problem has been around since 2.5.28,
and hasn't yet been fixed (As for a fix, Andrew Morton said "I'll sit tight for
the while, see where shed_yield() behaviour ends up").

All the best,

Duncan.
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