diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index c8c1dfc22c938a65171670ea50b92f692f6c1867..f612941ef46ed5aebc2fc86e40f343053d9afb3c 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -257,6 +257,14 @@ enum perf_event_type { */ PERF_EVENT_COMM = 3, + /* + * struct { + * struct perf_event_header header; + * u64 irq_period; + * }; + */ + PERF_EVENT_PERIOD = 4, + /* * When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field * will be PERF_RECORD_* diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 64113e6d1942febe4400f2d87ebb4cd069473837..db02eb16c777fd273307b1d1eb26f9c2f78b5c66 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; } @@ -2406,6 +2410,40 @@ void perf_counter_munmap(unsigned long addr, unsigned long len, perf_counter_mmap_event(&mmap_event); } +/* + * + */ + +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. */