* [PATCH] update sc->nr_reclaimed after each shrink_slab
@ 2016-07-22 3:43 ` Zhou Chengming
0 siblings, 0 replies; 8+ messages in thread
From: Zhou Chengming @ 2016-07-22 3:43 UTC (permalink / raw)
To: linux-kernel, linux-mm
Cc: akpm, vdavydov, riel, mhocko, guohanjun, zhouchengming1
In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
value to see if we can break out.
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
---
mm/vmscan.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c4a2f45..47133c3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2405,6 +2405,11 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
memcg, sc->nr_scanned - scanned,
lru_pages);
+ if (!global_reclaim(sc) && reclaim_state) {
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ reclaim_state->reclaimed_slab = 0;
+ }
+
/* Record the group's reclaim efficiency */
vmpressure(sc->gfp_mask, memcg, false,
sc->nr_scanned - scanned,
--
1.7.7
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] update sc->nr_reclaimed after each shrink_slab
@ 2016-07-22 3:43 ` Zhou Chengming
0 siblings, 0 replies; 8+ messages in thread
From: Zhou Chengming @ 2016-07-22 3:43 UTC (permalink / raw)
To: linux-kernel, linux-mm
Cc: akpm, vdavydov, riel, mhocko, guohanjun, zhouchengming1
In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
value to see if we can break out.
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
---
mm/vmscan.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c4a2f45..47133c3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2405,6 +2405,11 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
memcg, sc->nr_scanned - scanned,
lru_pages);
+ if (!global_reclaim(sc) && reclaim_state) {
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ reclaim_state->reclaimed_slab = 0;
+ }
+
/* Record the group's reclaim efficiency */
vmpressure(sc->gfp_mask, memcg, false,
sc->nr_scanned - scanned,
--
1.7.7
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
2016-07-22 3:43 ` Zhou Chengming
@ 2016-07-22 7:49 ` Michal Hocko
-1 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2016-07-22 7:49 UTC (permalink / raw)
To: Zhou Chengming; +Cc: linux-kernel, linux-mm, akpm, vdavydov, riel, guohanjun
On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> value to see if we can break out.
Does this actually change anything? Maybe I am missing something but
try_to_free_mem_cgroup_pages which is the main entry for the memcg
reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
Have you observed any issues and this patch fixes it or this is just
motivated by the code inspection?
> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
> ---
> mm/vmscan.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index c4a2f45..47133c3 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -2405,6 +2405,11 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
> memcg, sc->nr_scanned - scanned,
> lru_pages);
>
> + if (!global_reclaim(sc) && reclaim_state) {
> + sc->nr_reclaimed += reclaim_state->reclaimed_slab;
> + reclaim_state->reclaimed_slab = 0;
> + }
> +
> /* Record the group's reclaim efficiency */
> vmpressure(sc->gfp_mask, memcg, false,
> sc->nr_scanned - scanned,
> --
> 1.7.7
>
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
@ 2016-07-22 7:49 ` Michal Hocko
0 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2016-07-22 7:49 UTC (permalink / raw)
To: Zhou Chengming; +Cc: linux-kernel, linux-mm, akpm, vdavydov, riel, guohanjun
On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> value to see if we can break out.
Does this actually change anything? Maybe I am missing something but
try_to_free_mem_cgroup_pages which is the main entry for the memcg
reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
Have you observed any issues and this patch fixes it or this is just
motivated by the code inspection?
> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
> ---
> mm/vmscan.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index c4a2f45..47133c3 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -2405,6 +2405,11 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
> memcg, sc->nr_scanned - scanned,
> lru_pages);
>
> + if (!global_reclaim(sc) && reclaim_state) {
> + sc->nr_reclaimed += reclaim_state->reclaimed_slab;
> + reclaim_state->reclaimed_slab = 0;
> + }
> +
> /* Record the group's reclaim efficiency */
> vmpressure(sc->gfp_mask, memcg, false,
> sc->nr_scanned - scanned,
> --
> 1.7.7
>
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
2016-07-22 7:49 ` Michal Hocko
@ 2016-07-22 8:12 ` Vladimir Davydov
-1 siblings, 0 replies; 8+ messages in thread
From: Vladimir Davydov @ 2016-07-22 8:12 UTC (permalink / raw)
To: Michal Hocko
Cc: Zhou Chengming, linux-kernel, linux-mm, akpm, riel, guohanjun
On Fri, Jul 22, 2016 at 09:49:13AM +0200, Michal Hocko wrote:
> On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> > In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> > shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> > value to see if we can break out.
>
> Does this actually change anything? Maybe I am missing something but
> try_to_free_mem_cgroup_pages which is the main entry for the memcg
> reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
We don't set reclaim_state on memcg reclaim, because there might be a
lot of unrelated slab objects freed from the interrupt context (e.g.
RCU freed) while we're doing memcg reclaim. Obviously, we don't want
them to contribute to nr_reclaimed.
Link to the thread with the problem discussion:
http://marc.info/?l=linux-kernel&m=142132698209680&w=2
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
@ 2016-07-22 8:12 ` Vladimir Davydov
0 siblings, 0 replies; 8+ messages in thread
From: Vladimir Davydov @ 2016-07-22 8:12 UTC (permalink / raw)
To: Michal Hocko
Cc: Zhou Chengming, linux-kernel, linux-mm, akpm, riel, guohanjun
On Fri, Jul 22, 2016 at 09:49:13AM +0200, Michal Hocko wrote:
> On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> > In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> > shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> > value to see if we can break out.
>
> Does this actually change anything? Maybe I am missing something but
> try_to_free_mem_cgroup_pages which is the main entry for the memcg
> reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
We don't set reclaim_state on memcg reclaim, because there might be a
lot of unrelated slab objects freed from the interrupt context (e.g.
RCU freed) while we're doing memcg reclaim. Obviously, we don't want
them to contribute to nr_reclaimed.
Link to the thread with the problem discussion:
http://marc.info/?l=linux-kernel&m=142132698209680&w=2
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
2016-07-22 8:12 ` Vladimir Davydov
@ 2016-07-22 8:18 ` Michal Hocko
-1 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2016-07-22 8:18 UTC (permalink / raw)
To: Vladimir Davydov
Cc: Zhou Chengming, linux-kernel, linux-mm, akpm, riel, guohanjun
On Fri 22-07-16 11:12:59, Vladimir Davydov wrote:
> On Fri, Jul 22, 2016 at 09:49:13AM +0200, Michal Hocko wrote:
> > On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> > > In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> > > shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> > > value to see if we can break out.
> >
> > Does this actually change anything? Maybe I am missing something but
> > try_to_free_mem_cgroup_pages which is the main entry for the memcg
> > reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
>
> We don't set reclaim_state on memcg reclaim, because there might be a
> lot of unrelated slab objects freed from the interrupt context (e.g.
> RCU freed) while we're doing memcg reclaim. Obviously, we don't want
> them to contribute to nr_reclaimed.
>
> Link to the thread with the problem discussion:
>
> http://marc.info/?l=linux-kernel&m=142132698209680&w=2
Ohh, now I rememeber again. Thanks for the refresh ;)
So the patch doesn't make any difference in the end.
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] update sc->nr_reclaimed after each shrink_slab
@ 2016-07-22 8:18 ` Michal Hocko
0 siblings, 0 replies; 8+ messages in thread
From: Michal Hocko @ 2016-07-22 8:18 UTC (permalink / raw)
To: Vladimir Davydov
Cc: Zhou Chengming, linux-kernel, linux-mm, akpm, riel, guohanjun
On Fri 22-07-16 11:12:59, Vladimir Davydov wrote:
> On Fri, Jul 22, 2016 at 09:49:13AM +0200, Michal Hocko wrote:
> > On Fri 22-07-16 11:43:30, Zhou Chengming wrote:
> > > In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each
> > > shrink_slab in the loop. Because we need the correct sc->nr_reclaimed
> > > value to see if we can break out.
> >
> > Does this actually change anything? Maybe I am missing something but
> > try_to_free_mem_cgroup_pages which is the main entry for the memcg
> > reclaim doesn't set reclaim_state. I don't remember why... Vladimir?
>
> We don't set reclaim_state on memcg reclaim, because there might be a
> lot of unrelated slab objects freed from the interrupt context (e.g.
> RCU freed) while we're doing memcg reclaim. Obviously, we don't want
> them to contribute to nr_reclaimed.
>
> Link to the thread with the problem discussion:
>
> http://marc.info/?l=linux-kernel&m=142132698209680&w=2
Ohh, now I rememeber again. Thanks for the refresh ;)
So the patch doesn't make any difference in the end.
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-07-22 9:47 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-07-22 3:43 [PATCH] update sc->nr_reclaimed after each shrink_slab Zhou Chengming
2016-07-22 3:43 ` Zhou Chengming
2016-07-22 7:49 ` Michal Hocko
2016-07-22 7:49 ` Michal Hocko
2016-07-22 8:12 ` Vladimir Davydov
2016-07-22 8:12 ` Vladimir Davydov
2016-07-22 8:18 ` Michal Hocko
2016-07-22 8:18 ` Michal Hocko
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.