3 files changed, 27 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index afc2413ba00..9e581c5cf6d 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -726,6 +726,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 {
 	struct event_constraint *c;
 	unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
+	struct perf_event *e;
 	int i, wmin, wmax, num = 0;
 	struct hw_perf_event *hwc;
 
@@ -770,13 +771,31 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 					 wmax, assign);
 
 	/*
+	 * Mark the event as committed, so we do not put_constraint()
+	 * in case new events are added and fail scheduling.
+	 */
+	if (!num && assign) {
+		for (i = 0; i < n; i++) {
+			e = cpuc->event_list[i];
+			e->hw.flags |= PERF_X86_EVENT_COMMITTED;
+		}
+	}
+	/*
 	 * scheduling failed or is just a simulation,
 	 * free resources if necessary
 	 */
 	if (!assign || num) {
 		for (i = 0; i < n; i++) {
+			e = cpuc->event_list[i];
+			/*
+			 * do not put_constraint() on comitted events,
+			 * because they are good to go
+			 */
+			if ((e->hw.flags & PERF_X86_EVENT_COMMITTED))
+				continue;
+
 			if (x86_pmu.put_event_constraints)
-				x86_pmu.put_event_constraints(cpuc, cpuc->event_list[i]);
+				x86_pmu.put_event_constraints(cpuc, e);
 		}
 	}
 	return num ? -EINVAL : 0;
@@ -1156,6 +1175,11 @@ static void x86_pmu_del(struct perf_event *event, int flags)
 	int i;
 
 	/*
+	 * event is descheduled
+	 */
+	event->hw.flags &= ~PERF_X86_EVENT_COMMITTED;
+
+	/*
 	 * If we're called during a txn, we don't need to do anything.
 	 * The events never got scheduled and ->cancel_txn will truncate
 	 * the event_list.
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 4809f075d97..97e557bc4c9 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -63,11 +63,12 @@ struct event_constraint {
 	int	flags;
 };
 /*
- * struct event_constraint flags
+ * struct hw_perf_event.flags flags
  */
 #define PERF_X86_EVENT_PEBS_LDLAT	0x1 /* ld+ldlat data address sampling */
 #define PERF_X86_EVENT_PEBS_ST		0x2 /* st data address sampling */
 #define PERF_X86_EVENT_PEBS_ST_HSW	0x4 /* haswell style st data sampling */
+#define PERF_X86_EVENT_COMMITTED	0x8 /* event passed commit_txn */
 
 struct amd_nb {
 	int nb_id;  /* NorthBridge id */
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 5877f372b03..fbc9210b45b 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1450,7 +1450,6 @@ x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event)
 	if (x86_pmu.event_constraints) {
 		for_each_event_constraint(c, x86_pmu.event_constraints) {
 			if ((event->hw.config & c->cmask) == c->code) {
-				/* hw.flags zeroed at initialization */
 				event->hw.flags |= c->flags;
 				return c;
 			}
@@ -1498,7 +1497,6 @@ intel_put_shared_regs_event_constraints(struct cpu_hw_events *cpuc,
 static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
 					struct perf_event *event)
 {
-	event->hw.flags = 0;
 	intel_put_shared_regs_event_constraints(cpuc, event);
 }