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Commit 272d30be authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

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: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100122155535.963944926@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 63b14649

arch/x86/kernel/cpu/perf_event.c

+5 −4
Original line number Diff line number Diff line
@@ -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) {