]> git.baikalelectronics.ru Git - kernel.git/commit
s390/locking: Reenable optimistic spinning
authorChristian Borntraeger <borntraeger@de.ibm.com>
Tue, 5 Aug 2014 07:57:51 +0000 (09:57 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 6 Aug 2014 09:44:43 +0000 (11:44 +0200)
commit3d60309a9784cdc2a72128ed9d3631d93310f64a
treefdc1603d6ea44a5c9033f4d1804d982e23708b71
parenta54b8e5d1339b78880b53a29dc08548b871c8149
s390/locking: Reenable optimistic spinning

commit 8a5f2ff29534f02d7d0747738a6cfe2ccaffaf5b (locking/mutex: Disable
optimistic spinning on some architectures) fenced spinning for
architectures without proper cmpxchg.
There is no need to disable mutex spinning on s390, though:
The instructions CS,CSG and friends provide the proper guarantees.
(We dont implement cmpxchg with locks).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/Kconfig