From 272d30be622c9c6cbd514b1211ff359292001baa Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 22 Jan 2010 16:32:17 +0100 Subject: [PATCH] perf_event: x86: Optimize constraint weight computation Add a weight member to the constraint structure and avoid recomputing the weight at runtime. Signed-off-by: Peter Zijlstra Cc: Stephane Eranian LKML-Reference: <20100122155535.963944926@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 092ad56..2c22ce4 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -76,6 +77,7 @@ struct event_constraint { }; int code; int cmask; + int weight; }; struct cpu_hw_events { @@ -95,6 +97,7 @@ struct cpu_hw_events { { .idxmsk64[0] = (n) }, \ .code = (c), \ .cmask = (m), \ + .weight = HWEIGHT64((u64)(n)), \ } #define INTEL_EVENT_CONSTRAINT(c, n) \ @@ -1242,8 +1245,7 @@ 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; - int weight, wmax; + 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)]; struct hw_perf_event *hwc; @@ -1320,8 +1322,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign) c = constraints[i]; hwc = &cpuc->event_list[i]->hw; - weight = bitmap_weight(c->idxmsk, X86_PMC_IDX_MAX); - if (weight != w) + if (c->weight != w) continue; for_each_bit(j, c->idxmsk, X86_PMC_IDX_MAX) { -- 2.7.4