diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-15 15:19:28 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-15 15:26:56 +0200 |
| commit | 60db5e09c13109b13830cc9dcae688003fd39e79 (patch) | |
| tree | ac923b89c28d735d2460216202d960e9c6237be0 /arch | |
| parent | 789f90fcf6b0b54e655740e9396c954378542c79 (diff) | |
perf_counter: frequency based adaptive irq_period
Instead of specifying the irq_period for a counter, provide a target interrupt
frequency and dynamically adapt the irq_period to match this frequency.
[ Impact: new perf-counter attribute/feature ]
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>
LKML-Reference: <20090515132018.646195868@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/perf_counter.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 9 |
2 files changed, 9 insertions, 13 deletions
diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c index bb1b463c136..db8d5cafc15 100644 --- a/arch/powerpc/kernel/perf_counter.c +++ b/arch/powerpc/kernel/perf_counter.c @@ -534,7 +534,7 @@ void hw_perf_enable(void) continue; } val = 0; - if (counter->hw_event.irq_period) { + if (counter->hw.irq_period) { left = atomic64_read(&counter->hw.period_left); if (left < 0x80000000L) val = 0x80000000L - left; @@ -829,8 +829,6 @@ const struct pmu *hw_perf_counter_init(struct perf_counter *counter) if (!ppmu) return ERR_PTR(-ENXIO); - if ((s64)counter->hw_event.irq_period < 0) - return ERR_PTR(-EINVAL); if (!perf_event_raw(&counter->hw_event)) { ev = perf_event_id(&counter->hw_event); if (ev >= ppmu->n_generic || ppmu->generic_events[ev] == 0) @@ -901,7 +899,7 @@ const struct pmu *hw_perf_counter_init(struct perf_counter *counter) counter->hw.config = events[n]; counter->hw.counter_base = cflags[n]; - atomic64_set(&counter->hw.period_left, counter->hw_event.irq_period); + atomic64_set(&counter->hw.period_left, counter->hw.irq_period); /* * See if we need to reserve the PMU. @@ -934,6 +932,7 @@ const struct pmu *hw_perf_counter_init(struct perf_counter *counter) static void record_and_restart(struct perf_counter *counter, long val, struct pt_regs *regs, int nmi) { + u64 period = counter->hw.irq_period; s64 prev, delta, left; int record = 0; @@ -948,11 +947,11 @@ static void record_and_restart(struct perf_counter *counter, long val, */ val = 0; left = atomic64_read(&counter->hw.period_left) - delta; - if (counter->hw_event.irq_period) { + if (period) { if (left <= 0) { - left += counter->hw_event.irq_period; + left += period; if (left <= 0) - left = counter->hw_event.irq_period; + left = period; record = 1; } if (left < 0x80000000L) diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 5a7f718eb1e..886dcf334bc 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -286,11 +286,8 @@ static int __hw_perf_counter_init(struct perf_counter *counter) hwc->nmi = 1; } - hwc->irq_period = hw_event->irq_period; - if ((s64)hwc->irq_period <= 0 || hwc->irq_period > x86_pmu.max_period) - hwc->irq_period = x86_pmu.max_period; - - atomic64_set(&hwc->period_left, hwc->irq_period); + atomic64_set(&hwc->period_left, + min(x86_pmu.max_period, hwc->irq_period)); /* * Raw event type provide the config in the event structure @@ -458,7 +455,7 @@ x86_perf_counter_set_period(struct perf_counter *counter, struct hw_perf_counter *hwc, int idx) { s64 left = atomic64_read(&hwc->period_left); - s64 period = hwc->irq_period; + s64 period = min(x86_pmu.max_period, hwc->irq_period); int err; /* |