Date: Wed, 16 Jan 2008 19:00:07 GMT From: Thomas Hurst <tom@hur.st> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/114438: [amr] Anomalous performance with multiple arrays and amr(4) Message-ID: <200801161900.m0GJ07d9061707@freefall.freebsd.org>
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The following reply was made to PR kern/114438; it has been noted by GNATS.
From: Thomas Hurst <tom@hur.st>
To: bug-followup@FreeBSD.org
Cc:
Subject: Re: kern/114438: [amr] Anomalous performance with multiple arrays
and amr(4)
Date: Wed, 16 Jan 2008 18:33:55 +0000
Further investigation would seem to implicate atime updates; every time
reads from one array freeze, the other array has an IO queue depth (as
reported by gstat) of ~1000 and is performing a bunch of writes.
Ignoring the meta-issue of all those atime updates, it would seem the
large work queue to one array on the card starves out other arrays.
My recent tests for this have been on 7.0-RC1 as of today.
--
Thomas 'Freaky' Hurst
http://hur.st/
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