perf/core: Verify we have a single perf_hw_context PMU
authorPeter Zijlstra <peterz@infradead.org>
Tue, 22 Mar 2016 21:09:18 +0000 (22:09 +0100)
committerIngo Molnar <mingo@kernel.org>
Thu, 31 Mar 2016 08:30:41 +0000 (10:30 +0200)
commit26657848502b78474a5f17f9ce2ae6dc8d8d6262
tree8fe05c327ca5f72701709dd25ff4f90bdce43d03
parent07dc900e17a94681877b5797ce62ba97fa170400
perf/core: Verify we have a single perf_hw_context PMU

There should (and can) only be a single PMU for perf_hw_context
events.

This is because of how we schedule events: once a hardware event fails to
schedule (the PMU is 'full') we stop trying to add more. The trivial
'fix' would break the Round-Robin scheduling we do.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/events/core.c