From: Peter Zijlstra Date: Fri, 22 Jan 2010 15:40:12 +0000 (+0100) Subject: perf_event: x86: Optimize the fast path a little more X-Git-Tag: upstream/snapshot3+hdmi~15500^2~83 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c933c1a603d5bf700ddce79216c1be0ec3bc0e6c;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git perf_event: x86: Optimize the fast path a little more Remove num from the fast path and save a few ops. Signed-off-by: Peter Zijlstra Cc: Stephane Eranian LKML-Reference: <20100122155536.056430539@chello.nl> Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 2c22ce4..33c889f 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1245,9 +1245,9 @@ static inline int is_x86_event(struct perf_event *event) static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) { - int i, j, w, num, wmax; struct event_constraint *c, *constraints[X86_PMC_IDX_MAX]; unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)]; + int i, j, w, wmax, num = 0; struct hw_perf_event *hwc; bitmap_zero(used_mask, X86_PMC_IDX_MAX); @@ -1260,7 +1260,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) /* * fastpath, try to reuse previous register */ - for (i = 0, num = n; i < n; i++, num--) { + for (i = 0; i < n; i++) { hwc = &cpuc->event_list[i]->hw; c = constraints[i]; @@ -1288,7 +1288,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) if (assign) assign[i] = hwc->idx; } - if (!num) + if (i == n) goto done; /*