Currently the perf_events_attr::wakeup_events logic is checked only for regular samples.
If we have an event that produce only auxiliary events (MMAP|COMM|EXIT|FORK), the poll call does not follow the perf_events_attr wakeup_events setup and reports no data. Fixing this by moving the perf_events_attr::wakeup_events checking logic into the function and calling it from perf_output_end. This way any output event is checked properly. Signed-off-by: Jiri Olsa <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Corey Ashford <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Stephane Eranian <[email protected]> --- kernel/events/core.c | 14 -------------- kernel/events/ring_buffer.c | 20 ++++++++++++++++++++ 2 files changed, 20 insertions(+), 14 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index a0780b3..516eb25 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4281,20 +4281,6 @@ void perf_output_sample(struct perf_output_handle *handle, } } - if (!event->attr.watermark) { - int wakeup_events = event->attr.wakeup_events; - - if (wakeup_events) { - struct ring_buffer *rb = handle->rb; - int events = local_inc_return(&rb->events); - - if (events >= wakeup_events) { - local_sub(wakeup_events, &rb->events); - local_inc(&rb->wakeup); - } - } - } - if (sample_type & PERF_SAMPLE_BRANCH_STACK) { if (data->br_stack) { size_t size; diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index cd55144..1385fb1 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -54,6 +54,25 @@ static void perf_output_wakeup(struct perf_output_handle *handle) irq_work_queue(&handle->event->pending); } +static void perf_output_check_wakeup(struct perf_output_handle *handle) +{ + struct perf_event *event = handle->event; + + if (!event->attr.watermark) { + int wakeup_events = event->attr.wakeup_events; + + if (wakeup_events) { + struct ring_buffer *rb = handle->rb; + int events = local_inc_return(&rb->events); + + if (events >= wakeup_events) { + local_sub(wakeup_events, &rb->events); + local_inc(&rb->wakeup); + } + } + } +} + /* * We need to ensure a later event_id doesn't publish a head when a former * event isn't done writing. However since we need to deal with NMIs we @@ -208,6 +227,7 @@ unsigned int perf_output_skip(struct perf_output_handle *handle, void perf_output_end(struct perf_output_handle *handle) { + perf_output_check_wakeup(handle); perf_output_put_handle(handle); rcu_read_unlock(); } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
