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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-20 12:21:20 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-20 12:43:33 +0200 |
| commit | 26b119bc811a73bac6ecf95bdf284bf31c7955f0 (patch) | |
| tree | cc8b39284012c27c4014c253655cff7ee95f79ce /kernel | |
| parent | d7b629a34fc4134a43c730b5f0197855dc4948d0 (diff) | |
| download | linux-26b119bc811a73bac6ecf95bdf284bf31c7955f0.tar.gz | |
perf_counter: Log irq_period changes
For the dynamic irq_period code, log whenever we change the period so that
analyzing code can normalize the event flow.
[ Impact: add new feature to allow more precise profiling ]
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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090520102553.298769743@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/perf_counter.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 64113e6d1942..db02eb16c777 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1046,7 +1046,9 @@ int perf_counter_task_enable(void) return 0; } -void perf_adjust_freq(struct perf_counter_context *ctx) +static void perf_log_period(struct perf_counter *counter, u64 period); + +static void perf_adjust_freq(struct perf_counter_context *ctx) { struct perf_counter *counter; u64 irq_period; @@ -1072,6 +1074,8 @@ void perf_adjust_freq(struct perf_counter_context *ctx) if (!irq_period) irq_period = 1; + perf_log_period(counter, irq_period); + counter->hw.irq_period = irq_period; counter->hw.interrupts = 0; } @@ -2407,6 +2411,40 @@ void perf_counter_munmap(unsigned long addr, unsigned long len, } /* + * + */ + +static void perf_log_period(struct perf_counter *counter, u64 period) +{ + struct perf_output_handle handle; + int ret; + + struct { + struct perf_event_header header; + u64 time; + u64 period; + } freq_event = { + .header = { + .type = PERF_EVENT_PERIOD, + .misc = 0, + .size = sizeof(freq_event), + }, + .time = sched_clock(), + .period = period, + }; + + if (counter->hw.irq_period == period) + return; + + ret = perf_output_begin(&handle, counter, sizeof(freq_event), 0, 0); + if (ret) + return; + + perf_output_put(&handle, freq_event); + perf_output_end(&handle); +} + +/* * Generic counter overflow handling. */ |