This is a note to let you know that I've just added the patch titled
s390/pai: cleanup event initialization
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-pai-cleanup-event-initialization.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 69d64bafe3b1c1f9a8323476b900b64001a304e9
Author: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Date: Mon Oct 30 11:41:33 2023 +0100
s390/pai: cleanup event initialization
[ Upstream commit 4711b7b8f99583f6105a33e91f106125134beacb ]
Setting event::hw.last_tag to zero is not necessary. The memory
for each event is dynamically allocated by the kernel common code and
initialized to zero already. Remove this unnecessary assignment.
Move the comment to function paicrypt_start() for clarification.
Suggested-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Acked-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Stable-dep-of: e9f3af02f639 ("s390/pai: fix sampling event removal for PMU device driver")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/s390/kernel/perf_pai_crypto.c b/arch/s390/kernel/perf_pai_crypto.c
index 1ac74333a78dc..270255acacb02 100644
--- a/arch/s390/kernel/perf_pai_crypto.c
+++ b/arch/s390/kernel/perf_pai_crypto.c
@@ -210,12 +210,6 @@ static int paicrypt_event_init(struct perf_event *event)
if (rc)
return rc;
- /* Event initialization sets last_tag to 0. When later on the events
- * are deleted and re-added, do not reset the event count value to zero.
- * Events are added, deleted and re-added when 2 or more events
- * are active at the same time.
- */
- event->hw.last_tag = 0;
event->destroy = paicrypt_event_destroy;
if (a->sample_period) {
@@ -249,6 +243,11 @@ static void paicrypt_start(struct perf_event *event, int flags)
{
u64 sum;
+ /* Event initialization sets last_tag to 0. When later on the events
+ * are deleted and re-added, do not reset the event count value to zero.
+ * Events are added, deleted and re-added when 2 or more events
+ * are active at the same time.
+ */
if (!event->hw.last_tag) {
event->hw.last_tag = 1;
sum = paicrypt_getall(event); /* Get current value */
diff --git a/arch/s390/kernel/perf_pai_ext.c b/arch/s390/kernel/perf_pai_ext.c
index ac32107167eac..8fddde11cfb1f 100644
--- a/arch/s390/kernel/perf_pai_ext.c
+++ b/arch/s390/kernel/perf_pai_ext.c
@@ -261,7 +261,6 @@ static int paiext_event_init(struct perf_event *event)
rc = paiext_alloc(a, event);
if (rc)
return rc;
- event->hw.last_tag = 0;
event->destroy = paiext_event_destroy;
if (a->sample_period) {
