[tip:perf/urgent] perf: Optimize perf_disable
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From: tip-bot for Peter Zijlstra on 10 Mar 2010 08:20 Commit-ID: 32975a4f114be52286f9a5bf6c230dbb8c0e1903 Gitweb: http://git.kernel.org/tip/32975a4f114be52286f9a5bf6c230dbb8c0e1903 Author: Peter Zijlstra <a.p.zijlstra(a)chello.nl> AuthorDate: Sat, 6 Mar 2010 19:49:19 +0100 Committer: Ingo Molnar <mingo(a)elte.hu> CommitDate: Wed, 10 Mar 2010 13:22:25 +0100 perf: Optimize perf_disable Currently we always call hw_perf_disable(), even if its already disabled, this seems superflous, esp. since it cannot be made NMI safe (see further patches). Signed-off-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Cc: paulus(a)samba.org Cc: eranian(a)google.com Cc: robert.richter(a)amd.com Cc: fweisbec(a)gmail.com Cc: Arnaldo Carvalho de Melo <acme(a)infradead.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo(a)elte.hu> --- kernel/perf_event.c | 16 +++------------- 1 files changed, 3 insertions(+), 13 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 73329de..d810846 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -93,25 +93,15 @@ void __weak perf_event_print_debug(void) { } static DEFINE_PER_CPU(int, perf_disable_count); -void __perf_disable(void) -{ - __get_cpu_var(perf_disable_count)++; -} - -bool __perf_enable(void) -{ - return !--__get_cpu_var(perf_disable_count); -} - void perf_disable(void) { - __perf_disable(); - hw_perf_disable(); + if (!__get_cpu_var(perf_disable_count)++) + hw_perf_disable(); } void perf_enable(void) { - if (__perf_enable()) + if (!--__get_cpu_var(perf_disable_count)) hw_perf_enable(); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |