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perf_event: x86: Optimize the constraint searching bits 

Instead of copying bitmasks around, pass pointers to the constraint
structure.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100122155535.887853503@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 9f41699ed0
commit 63b146490b
1 changed files with 34 additions and 41 deletions
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75
arch/x86/kernel/cpu/perf_event.c
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@ -134,12 +134,14 @@ struct x86_pmu {
u64 intel_ctrl;
void (*enable_bts)(u64 config);
void (*disable_bts)(void);
void (*get_event_constraints)(struct cpu_hw_events *cpuc,
struct perf_event *event,
unsigned long *idxmsk);
struct event_constraint *
(*get_event_constraints)(struct cpu_hw_events *cpuc,
struct perf_event *event);
void (*put_event_constraints)(struct cpu_hw_events *cpuc,
struct perf_event *event);
const struct event_constraint *event_constraints;
struct event_constraint *event_constraints;
};
static struct x86_pmu x86_pmu __read_mostly;
@ -1242,17 +1244,15 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
{
int i, j , w, num;
int weight, wmax;
unsigned long *c;
unsigned long constraints[X86_PMC_IDX_MAX][BITS_TO_LONGS(X86_PMC_IDX_MAX)];
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;
bitmap_zero(used_mask, X86_PMC_IDX_MAX);
for (i = 0; i < n; i++) {
x86_pmu.get_event_constraints(cpuc,
cpuc->event_list[i],
constraints[i]);
constraints[i] =
x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]);
}
/*
@ -1267,7 +1267,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
break;
/* constraint still honored */
if (!test_bit(hwc->idx, c))
if (!test_bit(hwc->idx, c->idxmsk))
break;
/* not already used */
@ -1320,11 +1320,11 @@ 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, X86_PMC_IDX_MAX);
weight = bitmap_weight(c->idxmsk, X86_PMC_IDX_MAX);
if (weight != w)
continue;
for_each_bit(j, c, X86_PMC_IDX_MAX) {
for_each_bit(j, c->idxmsk, X86_PMC_IDX_MAX) {
if (!test_bit(j, used_mask))
break;
}
@ -2155,11 +2155,13 @@ perf_event_nmi_handler(struct notifier_block *self,
return NOTIFY_STOP;
}
static struct event_constraint unconstrained;
static struct event_constraint bts_constraint =
EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
static int intel_special_constraints(struct perf_event *event,
unsigned long *idxmsk)
static struct event_constraint *
intel_special_constraints(struct perf_event *event)
{
unsigned int hw_event;
@ -2169,46 +2171,34 @@ static int intel_special_constraints(struct perf_event *event,
x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS)) &&
(event->hw.sample_period == 1))) {
bitmap_copy((unsigned long *)idxmsk,
(unsigned long *)bts_constraint.idxmsk,
X86_PMC_IDX_MAX);
return 1;
return &bts_constraint;
}
return 0;
return NULL;
}
static void intel_get_event_constraints(struct cpu_hw_events *cpuc,
struct perf_event *event,
unsigned long *idxmsk)
static struct event_constraint *
intel_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
{
const struct event_constraint *c;
struct event_constraint *c;
/*
* cleanup bitmask
*/
bitmap_zero(idxmsk, X86_PMC_IDX_MAX);
if (intel_special_constraints(event, idxmsk))
return;
c = intel_special_constraints(event);
if (c)
return c;
if (x86_pmu.event_constraints) {
for_each_event_constraint(c, x86_pmu.event_constraints) {
if ((event->hw.config & c->cmask) == c->code) {
bitmap_copy(idxmsk, c->idxmsk, X86_PMC_IDX_MAX);
return;
}
if ((event->hw.config & c->cmask) == c->code)
return c;
}
}
/* no constraints, means supports all generic counters */
bitmap_fill((unsigned long *)idxmsk, x86_pmu.num_events);
return &unconstrained;
}
static void amd_get_event_constraints(struct cpu_hw_events *cpuc,
struct perf_event *event,
unsigned long *idxmsk)
static struct event_constraint *
amd_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
{
/* no constraints, means supports all generic counters */
bitmap_fill(idxmsk, x86_pmu.num_events);
return &unconstrained;
}
static int x86_event_sched_in(struct perf_event *event,
@ -2576,6 +2566,9 @@ void __init init_hw_perf_events(void)
perf_events_lapic_init();
register_die_notifier(&perf_event_nmi_notifier);
unconstrained = (struct event_constraint)
EVENT_CONSTRAINT(0, (1ULL << x86_pmu.num_events) - 1, 0);
pr_info("... version: %d\n", x86_pmu.version);
pr_info("... bit width: %d\n", x86_pmu.event_bits);
pr_info("... generic registers: %d\n", x86_pmu.num_events);