[PATCH v2 1/5] time/sched_clock: Swap update_clock_read_data() latch writes

From: Marco Elver
Date: Mon Nov 04 2024 - 11:20:05 EST


Swap the writes to the odd and even copies to make the writer critical
section look like all other seqcount_latch writers.

Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
v2:
* New patch.
---
kernel/time/sched_clock.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index 68d6c1190ac7..85595fcf6aa2 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -119,9 +119,6 @@ unsigned long long notrace sched_clock(void)
*/
static void update_clock_read_data(struct clock_read_data *rd)
{
- /* update the backup (odd) copy with the new data */
- cd.read_data[1] = *rd;
-
/* steer readers towards the odd copy */
raw_write_seqcount_latch(&cd.seq);

@@ -130,6 +127,9 @@ static void update_clock_read_data(struct clock_read_data *rd)

/* switch readers back to the even copy */
raw_write_seqcount_latch(&cd.seq);
+
+ /* update the backup (odd) copy with the new data */
+ cd.read_data[1] = *rd;
}

/*
--
2.47.0.163.g1226f6d8fa-goog