Merge branch 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Fix crash in swevents
  perf buildid-list: Fix --with-hits event processing
  perf scripts python: Give field dict to unhandled callback
  perf hist: fix objdump output parsing
  perf-record: Check correct pid when forking
  perf: Do the comm inheritance per thread in event__process_task
  perf: Use event__process_task from perf sched
  perf: Process comm events by tid
  blktrace: Fix new kernel-doc warnings
  perf_events: Fix unincremented buffer base on partial copy
  perf_events: Fix event scheduling issues introduced by transactional API
  perf_events, trace: Fix perf_trace_destroy(), mutex went missing
  perf_events, trace: Fix probe unregister race
  perf_events: Fix races in group composition
  perf_events: Fix races and clean up perf_event and perf_mmap_data interaction

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index c77586061bc..5db5b7d65a1 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -106,6 +106,7 @@ struct cpu_hw_events {
 
 	int			n_events;
 	int			n_added;
+	int			n_txn;
 	int			assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
 	u64			tags[X86_PMC_IDX_MAX];
 	struct perf_event	*event_list[X86_PMC_IDX_MAX]; /* in enabled order */
@@ -983,6 +984,7 @@ static int x86_pmu_enable(struct perf_event *event)
 out:
 	cpuc->n_events = n;
 	cpuc->n_added += n - n0;
+	cpuc->n_txn += n - n0;
 
 	return 0;
 }
@@ -1089,6 +1091,14 @@ static void x86_pmu_disable(struct perf_event *event)
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 	int i;
 
+	/*
+	 * 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.
+	 */
+	if (cpuc->group_flag & PERF_EVENT_TXN_STARTED)
+		return;
+
 	x86_pmu_stop(event);
 
 	for (i = 0; i < cpuc->n_events; i++) {
@@ -1379,6 +1389,7 @@ static void x86_pmu_start_txn(const struct pmu *pmu)
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 
 	cpuc->group_flag |= PERF_EVENT_TXN_STARTED;
+	cpuc->n_txn = 0;
 }
 
 /*
@@ -1391,6 +1402,11 @@ static void x86_pmu_cancel_txn(const struct pmu *pmu)
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 
 	cpuc->group_flag &= ~PERF_EVENT_TXN_STARTED;
+	/*
+	 * Truncate the collected events.
+	 */
+	cpuc->n_added -= cpuc->n_txn;
+	cpuc->n_events -= cpuc->n_txn;
 }
 
 /*
@@ -1419,6 +1435,12 @@ static int x86_pmu_commit_txn(const struct pmu *pmu)
 	 */
 	memcpy(cpuc->assign, assign, n*sizeof(int));
 
+	/*
+	 * Clear out the txn count so that ->cancel_txn() which gets
+	 * run after ->commit_txn() doesn't undo things.
+	 */
+	cpuc->n_txn = 0;
+
 	return 0;
 }