From a78ac3258782f3e64cb40beb5990808e1febcc0c Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 25 May 2009 17:39:05 +0200 Subject: 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 Cc: Paul Mackerras Cc: Corey Ashford Cc: Arnaldo Carvalho de Melo Cc: John Kacur LKML-Reference: <20090525153931.703093461@chello.nl> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_counter.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'arch') 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) -- cgit