perf: Allow storage of PMU private data in event

For PMUs which are not per CPU, but e.g. per package/socket, we want to be
able to store a reference to the underlying per package/socket facility in the
event at init time so we can avoid magic storage constructs in the PMU driver.

This allows us to get rid of the per CPU dance in the intel uncore and RAPL
drivers and avoids a lookup of the per package data in the perf hotpath.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Harish Chegondi <[email protected]>
Cc: Jacob Pan <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Vince Weaver <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: KAGA-KOKO

include/linux/perf_event.h

@@ -468,6 +468,7 @@ struct perf_event {
 	int				group_flags;
 	struct perf_event		*group_leader;
 	struct pmu			*pmu;
+	void				*pmu_private;
 
 	enum perf_event_active_state	state;
 	unsigned int			attach_state;