perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period
authorPeter Zijlstra <peterz@infradead.org>
Wed, 27 Nov 2013 13:54:38 +0000 (13:54 +0000)
committerIngo Molnar <mingo@kernel.org>
Tue, 17 Dec 2013 14:21:33 +0000 (15:21 +0100)
commitbad7192b842c83e580747ca57104dd51fe08c223
tree5a73fe2fc627384fa6ab621cc59433dc922f1155
parent7fd565e27547c913b83b46d94662103be81a88ec
perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period

Vince Weaver reports that, on all architectures apart from ARM,
PERF_EVENT_IOC_PERIOD doesn't actually update the period until the next
event fires. This is counter-intuitive behaviour and is better dealt
with in the core code.

This patch ensures that the period is forcefully reset when dealing with
such a request in the core code. A subsequent patch removes the
equivalent hack from the ARM back-end.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1385560479-11014-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/events/core.c