perf/x86: Add 3 new scheduling callbacks

This patch adds 3 new PMU model specific callbacks
during the event scheduling done by x86_schedule_events().

  ->start_scheduling():  invoked when entering the schedule routine.
  ->stop_scheduling():   invoked at the end of the schedule routine
  ->commit_scheduling(): invoked for each committed event

To be used optionally by model-specific code.

Signed-off-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: bp@alien8.de
Cc: jolsa@redhat.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1416251225-17721-4-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event.c

@@ -784,6 +784,9 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 
 	bitmap_zero(used_mask, X86_PMC_IDX_MAX);
 
+	if (x86_pmu.start_scheduling)
+		x86_pmu.start_scheduling(cpuc);
+
 	for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
 		hwc = &cpuc->event_list[i]->hw;
 		c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]);
@@ -830,6 +833,8 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 		for (i = 0; i < n; i++) {
 			e = cpuc->event_list[i];
 			e->hw.flags |= PERF_X86_EVENT_COMMITTED;
+			if (x86_pmu.commit_scheduling)
+				x86_pmu.commit_scheduling(cpuc, e, assign[i]);
 		}
 	}
 	/*
@@ -850,6 +855,10 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 				x86_pmu.put_event_constraints(cpuc, e);
 		}
 	}
+
+	if (x86_pmu.stop_scheduling)
+		x86_pmu.stop_scheduling(cpuc);
+
 	return num ? -EINVAL : 0;
 }
 

arch/x86/kernel/cpu/perf_event.h

@@ -460,6 +460,15 @@ struct x86_pmu {
 
 	void		(*put_event_constraints)(struct cpu_hw_events *cpuc,
 						 struct perf_event *event);
+
+	void		(*commit_scheduling)(struct cpu_hw_events *cpuc,
+					     struct perf_event *event,
+					     int cntr);
+
+	void		(*start_scheduling)(struct cpu_hw_events *cpuc);
+
+	void		(*stop_scheduling)(struct cpu_hw_events *cpuc);
+
 	struct event_constraint *event_constraints;
 	struct x86_pmu_quirk *quirks;
 	int		perfctr_second_write;