[S390] cpu topology: fix locking
authorHeiko Carstens <heiko.carstens@de.ibm.com>
Fri, 14 Nov 2008 17:18:07 +0000 (18:18 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 14 Nov 2008 17:18:54 +0000 (18:18 +0100)
commit74af283102b358b0da545460d0d176f473e110f6
tree5f5fc2faea5c40f6b597d6237ffa3f4a2e0585f4
parent85acc407bf1c49fb40b8f461c2c7526af736d87e
[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>
arch/s390/kernel/topology.c