From: Khazhismel Kumykov khazhy@google.com
[ 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@google.com Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/dm-ps-historical-service-time.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/md/dm-ps-historical-service-time.c b/drivers/md/dm-ps-historical-service-time.c index 875bca30a0dd..82f2a06153dc 100644 --- a/drivers/md/dm-ps-historical-service-time.c +++ b/drivers/md/dm-ps-historical-service-time.c @@ -27,7 +27,6 @@ #include <linux/blkdev.h> #include <linux/slab.h> #include <linux/module.h> -#include <linux/sched/clock.h>
#define DM_MSG_PREFIX "multipath historical-service-time" @@ -433,7 +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;
@@ -474,7 +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 @@ -483,11 +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,