Skip to contentSkip to conversation

perf fix

GIT PULL Merged Ingo Molnar 2 participants 2 messages Apr 7, 2024

Subsystems (2)
x86 perf events
lore
Share & tools
lore

Ingo Molnar

author
#0 lore raw

Linus,

Please pull the latest perf/urgent Git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2024-04-07

# HEAD: 312be9fc2234c8acfb8148a9f4c358b70d358dee perf/x86/intel/ds: Don't clear ->pebs_data_cfg for the last PEBS event

Fix a combined PEBS events bug on x86 Intel CPUs.

Thanks,

Ingo

------------------>
Kan Liang (1):

      perf/x86/intel/ds: Don't clear ->pebs_data_cfg for the last PEBS event
 arch/x86/events/intel/ds.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
arch/x86/events/intel/ds.c +4 -4
index 2641ba620f12..e010bfed8417 100644
@@ -1237,11 +1237,11 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
 	struct pmu *pmu = event->pmu;
 
 	/*
-	 * Make sure we get updated with the first PEBS
-	 * event. It will trigger also during removal, but
-	 * that does not hurt:
+	 * Make sure we get updated with the first PEBS event.
+	 * During removal, ->pebs_data_cfg is still valid for
+	 * the last PEBS event. Don't clear it.
 	 */
-	if (cpuc->n_pebs == 1)
+	if ((cpuc->n_pebs == 1) && add)
 		cpuc->pebs_data_cfg = PEBS_UPDATE_DS_SW;
 
 	if (needed_cb != pebs_needs_sched_cb(cpuc)) {