tree 1c695a1706daf6ef67c940c20a558fb7b9acbfb7
parent 19925ce778f9fc371b9607625de3bff04c60121e
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1267878298 +0100
committer Ingo Molnar <mingo@elte.hu> 1268223755 +0100

perf, x86: Fix double enable calls

hw_perf_enable() would enable already enabled events.

This causes problems with code that assumes that ->enable/->disable calls
are balanced (like the LBR code does).

What happens is that events that were already running and left in place
would get enabled again.

Avoid this by only enabling new events that match their previous
assignment.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>