Red Hat Bugzilla – Bug 114778
tight SCSI DMA pool due to incorrect resizing
Last modified: 2007-11-30 17:07:00 EST
(as reported on linux-scsi)
While running extensive SCSI tests with SUSE kernels and the zfcp
driver we hit bugs which stem from the vanilla 2.4 kernel.
This particular problem causes unnecessary memory constraints
in the SCSI subsystem. The SCSI midlayer holds out a pool of
upto 32 MB which is the exclusive memory source for SCSI operation.
Due to a faulty calculation 2.4 kernels might end up with a
fraction amount. This has been especially observed with large
SCSI configurations which demand more than 32 MB, and which
are in turn hit hardest.
This patch has been blessed by Jens Axboe, Mike Anderson,
and Kurt Garloff, who helped straightening this out.
Created attachment 97413 [details]
as posted on linux-scsi
Patch integrated into test kernel.
A fix for this problem has been committed to the RHEL3 U3
patch pool this evening (in kernel version 2.4.21-15.6.EL).
Adding to u3 blocker for tracking.
Moving back to assigned, as it appears there are still issues with the
Any details at hand?
This patch is included in the RHEL3 U3 kernel 2.4.21-20 and later.
An errata has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.