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Date: Thu, 22 Mar 2007 14:08:35 -0500
From: "Mr. Berkley Shands" <bshands@exegy.com>
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Subject: Quick fix for LSI8888ELP overruns in 2.6.20 and 2.6.21-rc4
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To: linux-xfs@oss.sgi.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org

My local kernel guru recognized this problem as a duplicate of the
LSI8408E bus lockup problem. The controller gets flooded with work,
and just climbs under a rock to hide. In the 8408E case, it
froze the PCI-e bus :-)

#!/bin/csh
#
# set the max request queue down from 128. any more than 32
# quickly slows down from 810MB/Sec to 11MB/Sec.
#
setenv X 32
#
foreach i ( /sys/block/sd{g,h,i,j,k,l,m,n}/queue/nr_requests)
   echo $X > $i
   end

Lots of time was spent in the congestion queue, like 99% of the time.

Berkley
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