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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-05-25 17:39:05 +0200
committerIngo Molnar <mingo@elte.hu>2009-05-25 21:41:12 +0200
commita78ac3258782f3e64cb40beb5990808e1febcc0c (patch)
tree692462a974e4c26bdb7fa7fae727a6b326a0eeee /arch/x86/kernel/cpu
parent48e22d56ecdeddd1ffb42a02fccba5c6ef42b133 (diff)
perf_counter: Generic per counter interrupt throttle
Introduce a generic per counter interrupt throttle. This uses the perf_counter_overflow() quick disable to throttle a specific counter when its going too fast when a pmu->unthrottle() method is provided which can undo the quick disable. Power needs to implement both the quick disable and the unthrottle method. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <20090525153931.703093461@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r--arch/x86/kernel/cpu/perf_counter.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 8c8177f859f..c4b543d1a86 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -623,6 +623,18 @@ try_generic:
return 0;
}
+static void x86_pmu_unthrottle(struct perf_counter *counter)
+{
+ struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+ struct hw_perf_counter *hwc = &counter->hw;
+
+ if (WARN_ON_ONCE(hwc->idx >= X86_PMC_IDX_MAX ||
+ cpuc->counters[hwc->idx] != counter))
+ return;
+
+ x86_pmu.enable(hwc, hwc->idx);
+}
+
void perf_counter_print_debug(void)
{
u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
@@ -1038,6 +1050,7 @@ static const struct pmu pmu = {
.enable = x86_pmu_enable,
.disable = x86_pmu_disable,
.read = x86_pmu_read,
+ .unthrottle = x86_pmu_unthrottle,
};
const struct pmu *hw_perf_counter_init(struct perf_counter *counter)