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dm mpath: only use ktime_get_ns() in historical selector

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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: 2613eab119 ("dm mpath: add Historical Service Time Path Selector")
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
This commit is contained in:
Khazhismel Kumykov 2022-04-11 15:03:35 -07:00 committed by Mike Snitzer
parent 08c1af8f1c
commit ce40426fdc
1 changed files with 5 additions and 6 deletions
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11
drivers/md/dm-ps-historical-service-time.c
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@ -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,