This is a note to let you know that I've just added the patch titled
dm mpath: only use ktime_get_ns() in historical selector
to the 5.15-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:
dm-mpath-only-use-ktime_get_ns-in-historical-selecto.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d944a5392b422a0721a00dfd87de491045451b79
Author: Khazhismel Kumykov <khazhy@xxxxxxxxxx>
Date: Mon Apr 11 15:03:35 2022 -0700
dm mpath: only use ktime_get_ns() in historical selector
[ Upstream commit ce40426fdc3c92acdba6b5ca74bc7277ffaa6a3d ]
Mixing sched_clock() and ktime_get_ns() usage will give bad results.
Switch hst_select_path() from using sched_clock() to ktime_get_ns().
Also rename path_service_time()'s 'sched_now' variable to 'now'.
Fixes: 2613eab11996 ("dm mpath: add Historical Service Time Path Selector")
Signed-off-by: Khazhismel Kumykov <khazhy@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-ps-historical-service-time.c b/drivers/md/dm-ps-historical-service-time.c
index 1856a1b125cc..82f2a06153dc 100644
--- a/drivers/md/dm-ps-historical-service-time.c
+++ b/drivers/md/dm-ps-historical-service-time.c
@@ -432,7 +432,7 @@ static struct dm_path *hst_select_path(struct path_selector *ps,
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
- u64 time_now = sched_clock();
+ u64 time_now = ktime_get_ns();
struct dm_path *ret = NULL;
unsigned long flags;
@@ -473,7 +473,7 @@ static int hst_start_io(struct path_selector *ps, struct dm_path *path,
static u64 path_service_time(struct path_info *pi, u64 start_time)
{
- u64 sched_now = ktime_get_ns();
+ u64 now = ktime_get_ns();
/* if a previous disk request has finished after this IO was
* sent to the hardware, pretend the submission happened
@@ -482,11 +482,11 @@ static u64 path_service_time(struct path_info *pi, u64 start_time)
if (time_after64(pi->last_finish, start_time))
start_time = pi->last_finish;
- pi->last_finish = sched_now;
- if (time_before64(sched_now, start_time))
+ pi->last_finish = now;
+ if (time_before64(now, start_time))
return 0;
- return sched_now - start_time;
+ return now - start_time;
}
static int hst_end_io(struct path_selector *ps, struct dm_path *path,
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
