perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples
authorWill Deacon <will.deacon@arm.com>
Fri, 23 Sep 2016 13:05:12 +0000 (14:05 +0100)
committerWill Deacon <will.deacon@arm.com>
Wed, 18 Oct 2017 11:53:31 +0000 (12:53 +0100)
commit085b30625e39df67d7320f22269796276c6b0c11
tree9a894a6253b6ccd4126bb921fbdc465a3182daa0
parentbc1d202023eb66f088f736ba423bee1cf135c720
perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples

The ARM SPE architecture permits an implementation to ignore a sample
if the sample is due to be taken whilst another sample is already being
produced. In this case, it is desirable to report the collision to
userspace, as they may want to lower the sample period.

This patch adds a PERF_AUX_FLAG_COLLISION flag, so that such events can
be relayed to userspace.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
include/uapi/linux/perf_event.h