perf: Optimize perf_output_*() by avoiding local_xchg()
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Tue, 18 May 2010 09:12:48 +0000 (11:12 +0200)
committerIngo Molnar <mingo@elte.hu>
Tue, 18 May 2010 16:35:49 +0000 (18:35 +0200)
commit6d1acfd5c6bfd5231c13a8f2858d7f2afbaa1b62
treeabcfa95947cafc94c978a255b814472fe67cad22
parentfa5881514ef9c9bcb29319aad85cf2d8889d91f1
perf: Optimize perf_output_*() by avoiding local_xchg()

Since the x86 XCHG ins implies LOCK, avoid the use by
using a sequence count instead.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
include/linux/perf_event.h
kernel/perf_event.c