From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Fri, 14 Nov 2008 17:18:07 +0000 (+0100)
Subject: [S390] cpu topology: fix locking
X-Git-Tag: v2.6.28-rc5~8^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74af283102b358b0da545460d0d176f473e110f6;p=pandora-kernel.git

[S390] cpu topology: fix locking

cpu_coregroup_map used to grab a mutex on s390 since it was only
called from process context.
Since c7c22e4d5c1fdebfac4dba76de7d0338c2b0d832 "block: add support
for IO CPU affinity" this is not true anymore.
It now also gets called from softirq context.

To prevent possible deadlocks change this in architecture code and
use a spinlock instead of a mutex.

Cc: stable@kernel.org
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

Reading git-diff-tree failed