Messages in this thread Patch in this message | | | From | "Naveen N. Rao" <> | Subject | [PATCH 1/2] kernel/events: Add option to notify through signals on wakeup | Date | Mon, 19 Jun 2017 20:01:07 +0530 |
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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 <naveen.n.rao@linux.vnet.ibm.com> --- include/uapi/linux/perf_event.h | 3 ++- kernel/events/core.c | 18 +++++++++++------- kernel/events/ring_buffer.c | 3 +++ 3 files changed, 16 insertions(+), 8 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..812fcfc767f4 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2679,7 +2679,8 @@ static int _perf_event_refresh(struct perf_event *event, int refresh) /* * not supported on inherited events */ - if (event->attr.inherit || !is_sampling_event(event)) + if (event->attr.inherit || event->attr.signal_on_wakeup || + !is_sampling_event(event)) return -EINVAL; atomic_add(refresh, &event->event_limit); @@ -7339,7 +7340,6 @@ static int __perf_event_overflow(struct perf_event *event, int throttle, struct perf_sample_data *data, struct pt_regs *regs) { - int events = atomic_read(&event->event_limit); int ret = 0; /* @@ -7362,12 +7362,15 @@ 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) { + int events = atomic_read(&event->event_limit); + 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); @@ -10408,6 +10411,7 @@ perf_event_exit_event(struct perf_event *child_event, perf_group_detach(child_event); list_del_event(child_event, child_ctx); child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */ + child_event->pending_kill = POLL_HUP; raw_spin_unlock_irq(&child_ctx->lock); /* 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); } -- 2.13.1
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