| Message ID | 20200711011459.1159929-1-shakeelb@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: vmscan: consistent update to pgrefill | expand |
On Sat, Jul 11, 2020 at 9:15 AM Shakeel Butt <shakeelb@google.com> wrote: > > The vmstat pgrefill is useful together with pgscan and pgsteal stats to > measure the reclaim efficiency. However vmstat's pgrefill is not updated > consistently at system level. It gets updated for both global and memcg > reclaim however pgscan and pgsteal are updated for only global reclaim. > So, update pgrefill only for global reclaim. If someone is interested in > the stats representing both system level as well as memcg level reclaim, > then consult the root memcg's memory.stat instead of /proc/vmstat. > > Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Yafang Shao <laoar.shao@gmail.com> > --- > mm/vmscan.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 5215840ee217..4167b0cc1784 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2030,7 +2030,8 @@ static void shrink_active_list(unsigned long nr_to_scan, > > __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken); > > - __count_vm_events(PGREFILL, nr_scanned); > + if (!cgroup_reclaim(sc)) > + __count_vm_events(PGREFILL, nr_scanned); > __count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned); > > spin_unlock_irq(&pgdat->lru_lock); > -- > 2.27.0.383.g050319c2ae-goog >
On Fri, Jul 10, 2020 at 06:14:59PM -0700, Shakeel Butt wrote: > The vmstat pgrefill is useful together with pgscan and pgsteal stats to > measure the reclaim efficiency. However vmstat's pgrefill is not updated > consistently at system level. It gets updated for both global and memcg > reclaim however pgscan and pgsteal are updated for only global reclaim. > So, update pgrefill only for global reclaim. If someone is interested in > the stats representing both system level as well as memcg level reclaim, > then consult the root memcg's memory.stat instead of /proc/vmstat. > > Signed-off-by: Shakeel Butt <shakeelb@google.com> So you went into the opposite direction from the "previous version" ( https://lkml.org/lkml/2020/5/7/1464 ) ? Acked-by: Roman Gushchin <guro@fb.com> Thanks!
On Fri, Jul 10, 2020 at 7:32 PM Roman Gushchin <guro@fb.com> wrote: > > On Fri, Jul 10, 2020 at 06:14:59PM -0700, Shakeel Butt wrote: > > The vmstat pgrefill is useful together with pgscan and pgsteal stats to > > measure the reclaim efficiency. However vmstat's pgrefill is not updated > > consistently at system level. It gets updated for both global and memcg > > reclaim however pgscan and pgsteal are updated for only global reclaim. > > So, update pgrefill only for global reclaim. If someone is interested in > > the stats representing both system level as well as memcg level reclaim, > > then consult the root memcg's memory.stat instead of /proc/vmstat. > > > > Signed-off-by: Shakeel Butt <shakeelb@google.com> > > So you went into the opposite direction from the "previous version" > ( https://lkml.org/lkml/2020/5/7/1464 ) ? > Yes because we already had those stats in the root memcg and exposing root memcg's memory.stat resolved the issue. > Acked-by: Roman Gushchin <guro@fb.com> Thanks a lot.
Shakeel Butt writes: >The vmstat pgrefill is useful together with pgscan and pgsteal stats to >measure the reclaim efficiency. However vmstat's pgrefill is not updated >consistently at system level. It gets updated for both global and memcg >reclaim however pgscan and pgsteal are updated for only global reclaim. >So, update pgrefill only for global reclaim. If someone is interested in >the stats representing both system level as well as memcg level reclaim, >then consult the root memcg's memory.stat instead of /proc/vmstat. > >Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Chris Down <chris@chrisdown.name>
diff --git a/mm/vmscan.c b/mm/vmscan.c index 5215840ee217..4167b0cc1784 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2030,7 +2030,8 @@ static void shrink_active_list(unsigned long nr_to_scan, __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken); - __count_vm_events(PGREFILL, nr_scanned); + if (!cgroup_reclaim(sc)) + __count_vm_events(PGREFILL, nr_scanned); __count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned); spin_unlock_irq(&pgdat->lru_lock);
The vmstat pgrefill is useful together with pgscan and pgsteal stats to measure the reclaim efficiency. However vmstat's pgrefill is not updated consistently at system level. It gets updated for both global and memcg reclaim however pgscan and pgsteal are updated for only global reclaim. So, update pgrefill only for global reclaim. If someone is interested in the stats representing both system level as well as memcg level reclaim, then consult the root memcg's memory.stat instead of /proc/vmstat. Signed-off-by: Shakeel Butt <shakeelb@google.com> --- mm/vmscan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)