diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-15 17:19:28 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-15 17:26:56 +0400 |
| commit | 60db5e09c13109b13830cc9dcae688003fd39e79 (patch) | |
| tree | ac923b89c28d735d2460216202d960e9c6237be0 /arch/x86/kernel/cpu/perf_counter.c | |
| parent | 789f90fcf6b0b54e655740e9396c954378542c79 (diff) | |
| download | linux-60db5e09c13109b13830cc9dcae688003fd39e79.tar.xz | |
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/x86/kernel/cpu/perf_counter.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 5a7f718eb1e1..886dcf334bc3 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; /* |