Add a new option 'signal_on_wakeup' to request for a signal to be
delivered on ring buffer wakeup controlled through watermark and
{wakeup_events, wakeup_watermark}.Signed-off-by: Naveen N. Rao <[email protected]> --- include/uapi/linux/perf_event.h | 3 ++- kernel/events/core.c | 12 +++++++----- kernel/events/ring_buffer.c | 3 +++ 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index b1c0b187acfe..e5810b1d74a4 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -345,7 +345,8 @@ struct perf_event_attr { context_switch : 1, /* context switch data */ write_backward : 1, /* Write ring buffer from end to beginning */ namespaces : 1, /* include namespaces data */ - __reserved_1 : 35; + signal_on_wakeup : 1, /* send signal on wakeup */ + __reserved_1 : 34; union { __u32 wakeup_events; /* wakeup every n events */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 6c4e523dc1e2..73ad30e124e5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7362,12 +7362,14 @@ static int __perf_event_overflow(struct perf_event *event, * events */ - event->pending_kill = POLL_IN; - if (events && atomic_dec_and_test(&event->event_limit)) { - ret = 1; - event->pending_kill = POLL_HUP; + if (!event->attr.signal_on_wakeup) { + event->pending_kill = POLL_IN; + if (events && atomic_dec_and_test(&event->event_limit)) { + ret = 1; + event->pending_kill = POLL_HUP; - perf_event_disable_inatomic(event); + perf_event_disable_inatomic(event); + } } READ_ONCE(event->overflow_handler)(event, data, regs); diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 2831480c63a2..4e7c728569a8 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -21,6 +21,9 @@ static void perf_output_wakeup(struct perf_output_handle *handle) { atomic_set(&handle->rb->poll, POLLIN); + if (handle->event->attr.signal_on_wakeup) + handle->event->pending_kill = POLL_IN; + handle->event->pending_wakeup = 1; irq_work_queue(&handle->event->pending); } -- 2.12.2
