From 1996bda2a42480c275656233e631ee0966574be4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 21 May 2010 14:05:13 +0200 Subject: arch: Implement local64_t On 64bit, local_t is of size long, and thus we make local64_t an alias. On 32bit, we fall back to atomic64_t. (architecture can provide optimized 32-bit version) (This new facility is to be used by perf events optimizations.) Signed-off-by: Peter Zijlstra Cc: linux-arch@vger.kernel.org Cc: Andrew Morton Cc: Linus Torvalds LKML-Reference: Signed-off-by: Ingo Molnar --- arch/sh/include/asm/local64.h | 1 + 1 file changed, 1 insertion(+) create mode 100644 arch/sh/include/asm/local64.h (limited to 'arch/sh') diff --git a/arch/sh/include/asm/local64.h b/arch/sh/include/asm/local64.h new file mode 100644 index 0000000..36c93b5 --- /dev/null +++ b/arch/sh/include/asm/local64.h @@ -0,0 +1 @@ +#include -- cgit v1.1 From e78505958cf123048fb48cb56b79cebb8edd15fb Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 21 May 2010 14:43:08 +0200 Subject: perf: Convert perf_event to local_t Since now all modification to event->count (and ->prev_count and ->period_left) are local to a cpu, change then to local64_t so we avoid the LOCK'ed ops. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- arch/sh/kernel/perf_event.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/sh') diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c index 81b6de4..7a3dc35 100644 --- a/arch/sh/kernel/perf_event.c +++ b/arch/sh/kernel/perf_event.c @@ -185,10 +185,10 @@ static void sh_perf_event_update(struct perf_event *event, * this is the simplest approach for maintaining consistency. */ again: - prev_raw_count = atomic64_read(&hwc->prev_count); + prev_raw_count = local64_read(&hwc->prev_count); new_raw_count = sh_pmu->read(idx); - if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count, + if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, new_raw_count) != prev_raw_count) goto again; @@ -203,7 +203,7 @@ again: delta = (new_raw_count << shift) - (prev_raw_count << shift); delta >>= shift; - atomic64_add(delta, &event->count); + local64_add(delta, &event->count); } static void sh_pmu_disable(struct perf_event *event) -- cgit v1.1