Messages in this thread Patch in this message | | | Date | Sun, 10 Jan 2016 13:53:26 +0200 | From | "Michael S. Tsirkin" <> | Subject | [PATCH] s390: more efficient smp barriers |
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As per: lkml.kernel.org/r/20150921112252.3c2937e1@mschwide atomics imply a barrier on s390, so s390 should change smp_mb__before_atomic and smp_mb__after_atomic to barrier() instead of smp_mb() and hence should not use the generic versions.
Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> ---
This is on top of arch barrier cleanup patchset, will be included in v3 of that patchset.
arch/s390/include/asm/barrier.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index 4d26fa4..5c8db3c 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -45,6 +45,9 @@ do { \ ___p1; \ }) +#define __smp_mb__before_atomic() barrier() +#define __smp_mb__after_atomic() barrier() + #include <asm-generic/barrier.h> #endif /* __ASM_BARRIER_H */ -- MST
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