s390/locking: Reenable optimistic spinning

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commit 36e7fdaa1a upstream.

commit 4badad352a (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>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Christian Borntraeger 2014-08-05 09:57:51 +02:00 • committed by Greg Kroah-Hartman

parent c301ca64d4

commit e54d01f3f2

1 changed files with 1 additions and 0 deletions

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arch/s390/Kconfig

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