From: Khazhismel Kumykov <khazhy@google.com>
To: Mike Snitzer <snitzer@kernel.org>, Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com, Khazhismel Kumykov <khazhy@google.com>,
Gabriel Krisman Bertazi <krisman@collabora.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] dm mpath: fixup sched_clock() usage in historical selector
Date: Mon, 11 Apr 2022 15:03:35 -0700 [thread overview]
Message-ID: <20220411220335.1235363-1-khazhy@google.com> (raw)
mixing sched_clock() and ktime_get_ns() will give bad results, don't do
it
Fixes: 2613eab11996 ("dm mpath: add Historical Service Time Path Selector")
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
---
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,
--
2.35.1.1178.g4f1659d476-goog
next reply other threads:[~2022-04-11 22:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-11 22:03 Khazhismel Kumykov [this message]
2022-04-11 23:48 ` [PATCH] dm mpath: fixup sched_clock() usage in historical selector Gabriel Krisman Bertazi
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