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perf_event: x86: Optimize the fast path a little more

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Remove num from the fast path and save a few ops.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100122155536.056430539@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2010-01-22 16:40:12 +01:00 committed by Ingo Molnar
parent 272d30be62
commit c933c1a603
1 changed files with 3 additions and 3 deletions
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6
arch/x86/kernel/cpu/perf_event.c
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@ -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) 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]; struct event_constraint *c, *constraints[X86_PMC_IDX_MAX];
unsigned long used_mask[BITS_TO_LONGS(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; struct hw_perf_event *hwc;
bitmap_zero(used_mask, X86_PMC_IDX_MAX); 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 * 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; hwc = &cpuc->event_list[i]->hw;
c = constraints[i]; c = constraints[i];
@ -1288,7 +1288,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
if (assign) if (assign)
assign[i] = hwc->idx; assign[i] = hwc->idx;
} }
if (!num) if (i == n)
goto done; goto done;
/* /*