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perf_event: x86: Optimize constraint weight computation

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Add a weight member to the constraint structure and avoid recomputing the
weight at runtime.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100122155535.963944926@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2010-01-22 16:32:17 +01:00 committed by Ingo Molnar
parent 63b146490b
commit 272d30be62
1 changed files with 5 additions and 4 deletions
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9
arch/x86/kernel/cpu/perf_event.c
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@ -23,6 +23,7 @@
#include <linux/uaccess.h>
#include <linux/highmem.h>
#include <linux/cpu.h>
#include <linux/bitops.h>
#include <asm/apic.h>
#include <asm/stacktrace.h>
@ -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) {