Messages in this thread | | | Date | Wed, 12 Jul 2017 12:48:55 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/2] kernel/events: Add option to enable counting sideband events in wakeup_events |
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On Mon, Jun 19, 2017 at 08:01:08PM +0530, Naveen N. Rao wrote:
SNIP
> - if (!event->attr.watermark) { > + if (!event->attr.count_sb_events && !event->attr.watermark) { > int wakeup_events = event->attr.wakeup_events; > > if (wakeup_events) { > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c > index 4e7c728569a8..f43a6081141f 100644 > --- a/kernel/events/ring_buffer.c > +++ b/kernel/events/ring_buffer.c > @@ -197,6 +197,19 @@ __perf_output_begin(struct perf_output_handle *handle, > * none of the data stores below can be lifted up by the compiler. > */ > > + if (event->attr.count_sb_events && !event->attr.watermark) { > + int wakeup_events = event->attr.wakeup_events; > + > + if (wakeup_events) { > + int events = local_inc_return(&rb->events); > + > + if (events >= wakeup_events) { > + local_sub(wakeup_events, &rb->events); > + local_inc(&rb->wakeup); > + } > + } > + }
hum, so there's the same wakeup code in perf_output_sample, but it's not called for non-sample (sideband) events
it'd be nice to have this wakeup only once in __perf_output_begin, but it'd change the behaviour for sideband events, which would start to follow the wakeup_events logic.. and possibly disturb Vince's tests?
jirka
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