* [PATCH] mm/vmscan: add pgstall to memcg
@ 2022-06-23 8:01 zhouchuyi
2022-06-24 20:42 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: zhouchuyi @ 2022-06-23 8:01 UTC (permalink / raw)
To: linux-mm; +Cc: akpm, zhouchuyi
Add pgstall to indicate the times of entering direct reclaim of memcg, use
the item of ALLOCSTALL_NORMAL in vmevents to save the data.
Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
---
Hi，
I notice memcg uses some items to indicate the situation of direct reclaim in memory.stat，such as pgsteal and pgscan.
I think there is no harm in adding another item to show the times of entering direct reclaim.
Thanks,
zhouchuyi
Documentation/admin-guide/cgroup-v2.rst | 7 +++++--
mm/memcontrol.c | 2 ++
mm/vmscan.c | 5 ++++-
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 176298f2f..44c5b15bd 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1447,8 +1447,11 @@ PAGE_SIZE multiple when read back.
pgsteal (npn)
Amount of reclaimed pages
-
- pgactivate (npn)
+
+ pgstall (npn)
+ Number of entering direct reclaim
+
+ pgactivate (npn)
Amount of pages moved to the active LRU list
pgdeactivate (npn)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index abec50f31..f407084b2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1505,6 +1505,8 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
seq_buf_printf(&s, "pgscan %lu\n",
memcg_events(memcg, PGSCAN_KSWAPD) +
memcg_events(memcg, PGSCAN_DIRECT));
+ seq_buf_printf(&s, "pgstall %lu\n",
+ memcg_events(memcg, ALLOCSTALL_NORMAL));
seq_buf_printf(&s, "pgsteal %lu\n",
memcg_events(memcg, PGSTEAL_KSWAPD) +
memcg_events(memcg, PGSTEAL_DIRECT));
diff --git a/mm/vmscan.c b/mm/vmscan.c
index f7d9a683e..107cec59a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3532,7 +3532,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
if (!cgroup_reclaim(sc))
__count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1);
-
+ else {
+ count_memcg_events(sc->target_mem_cgroup,
+ ALLOCSTALL_NORMAL, 1);
+ }
do {
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
sc->priority);
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] mm/vmscan: add pgstall to memcg
2022-06-23 8:01 [PATCH] mm/vmscan: add pgstall to memcg zhouchuyi
@ 2022-06-24 20:42 ` Andrew Morton
2022-07-12 9:28 ` Chuyi Zhou
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2022-06-24 20:42 UTC (permalink / raw)
To: zhouchuyi
Cc: linux-mm, Michal Hocko, Roman Gushchin, Johannes Weiner,
Shakeel Butt, Muchun Song
(cc memcg developers)
On Thu, 23 Jun 2022 16:01:03 +0800 zhouchuyi <zhouchuyi@bytedance.com> wrote:
> Add pgstall to indicate the times of entering direct reclaim of memcg, use
> the item of ALLOCSTALL_NORMAL in vmevents to save the data.
>
> Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
> ---
>
>
> Hi，
>
> I notice memcg uses some items to indicate the situation of direct reclaim in memory.stat，such as pgsteal and pgscan.
> I think there is no harm in adding another item to show the times of entering direct reclaim.
>
Why do you consider this useful? Do you have a use case? If so,
please describe it in detail.
>
> ...
>
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 176298f2f..44c5b15bd 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1447,8 +1447,11 @@ PAGE_SIZE multiple when read back.
>
> pgsteal (npn)
> Amount of reclaimed pages
> -
> - pgactivate (npn)
> +
> + pgstall (npn)
> + Number of entering direct reclaim
> +
> + pgactivate (npn)
> Amount of pages moved to the active LRU list
>
> pgdeactivate (npn)
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index abec50f31..f407084b2 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1505,6 +1505,8 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
> seq_buf_printf(&s, "pgscan %lu\n",
> memcg_events(memcg, PGSCAN_KSWAPD) +
> memcg_events(memcg, PGSCAN_DIRECT));
> + seq_buf_printf(&s, "pgstall %lu\n",
> + memcg_events(memcg, ALLOCSTALL_NORMAL));
> seq_buf_printf(&s, "pgsteal %lu\n",
> memcg_events(memcg, PGSTEAL_KSWAPD) +
> memcg_events(memcg, PGSTEAL_DIRECT));
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index f7d9a683e..107cec59a 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -3532,7 +3532,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
>
> if (!cgroup_reclaim(sc))
> __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1);
> -
> + else {
> + count_memcg_events(sc->target_mem_cgroup,
> + ALLOCSTALL_NORMAL, 1);
> + }
> do {
> vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
> sc->priority);
> --
> 2.20.1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mm/vmscan: add pgstall to memcg
2022-06-24 20:42 ` Andrew Morton
@ 2022-07-12 9:28 ` Chuyi Zhou
2022-07-12 13:55 ` Michal Hocko
0 siblings, 1 reply; 4+ messages in thread
From: Chuyi Zhou @ 2022-07-12 9:28 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-mm, Michal Hocko, Roman Gushchin, Johannes Weiner,
Shakeel Butt, Muchun Song
在 2022/6/25 上午4:42, Andrew Morton 写道:
> (cc memcg developers)
> On Thu, 23 Jun 2022 16:01:03 +0800 zhouchuyi <zhouchuyi@bytedance.com> wrote:
>
>> Add pgstall to indicate the times of entering direct reclaim of memcg, use
>> the item of ALLOCSTALL_NORMAL in vmevents to save the data.
>>
>> Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
>> ---
>>
>>
>> Hi，
>>
>> I notice memcg uses some items to indicate the situation of direct reclaim in memory.stat，such as pgsteal and pgscan.
>> I think there is no harm in adding another item to show the times of entering direct reclaim.
>>
>
> Why do you consider this useful? Do you have a use case? If so,
> please describe it in detail.
>
Since there are allocstall in proc/vmstat which indicate the number of
entering direct reclaim of !cgroup_reclaim, So I think it maybe useful.
For example, users could adjust memory.max to prevent entering direct
reclaim through this item.So what do you think about it ?
>>
>> ...
>>
>> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
>> index 176298f2f..44c5b15bd 100644
>> --- a/Documentation/admin-guide/cgroup-v2.rst
>> +++ b/Documentation/admin-guide/cgroup-v2.rst
>> @@ -1447,8 +1447,11 @@ PAGE_SIZE multiple when read back.
>>
>> pgsteal (npn)
>> Amount of reclaimed pages
>> -
>> - pgactivate (npn)
>> +
>> + pgstall (npn)
>> + Number of entering direct reclaim
>> +
>> + pgactivate (npn)
>> Amount of pages moved to the active LRU list
>>
>> pgdeactivate (npn)
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index abec50f31..f407084b2 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -1505,6 +1505,8 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
>> seq_buf_printf(&s, "pgscan %lu\n",
>> memcg_events(memcg, PGSCAN_KSWAPD) +
>> memcg_events(memcg, PGSCAN_DIRECT));
>> + seq_buf_printf(&s, "pgstall %lu\n",
>> + memcg_events(memcg, ALLOCSTALL_NORMAL));
>> seq_buf_printf(&s, "pgsteal %lu\n",
>> memcg_events(memcg, PGSTEAL_KSWAPD) +
>> memcg_events(memcg, PGSTEAL_DIRECT));
>> diff --git a/mm/vmscan.c b/mm/vmscan.c
>> index f7d9a683e..107cec59a 100644
>> --- a/mm/vmscan.c
>> +++ b/mm/vmscan.c
>> @@ -3532,7 +3532,10 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
>>
>> if (!cgroup_reclaim(sc))
>> __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1);
>> -
>> + else {
>> + count_memcg_events(sc->target_mem_cgroup,
>> + ALLOCSTALL_NORMAL, 1);
>> + }
>> do {
>> vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
>> sc->priority);
>> --
>> 2.20.1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] mm/vmscan: add pgstall to memcg
2022-07-12 9:28 ` Chuyi Zhou
@ 2022-07-12 13:55 ` Michal Hocko
0 siblings, 0 replies; 4+ messages in thread
From: Michal Hocko @ 2022-07-12 13:55 UTC (permalink / raw)
To: Chuyi Zhou
Cc: Andrew Morton, linux-mm, Roman Gushchin, Johannes Weiner,
Shakeel Butt, Muchun Song
On Tue 12-07-22 17:28:50, Chuyi Zhou wrote:
>
>
> 在 2022/6/25 上午4:42, Andrew Morton 写道:
> > (cc memcg developers)
> > On Thu, 23 Jun 2022 16:01:03 +0800 zhouchuyi <zhouchuyi@bytedance.com> wrote:
> >
> > > Add pgstall to indicate the times of entering direct reclaim of memcg, use
> > > the item of ALLOCSTALL_NORMAL in vmevents to save the data.
> > >
> > > Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
> > > ---
> > >
> > >
> > > Hi，
> > >
> > > I notice memcg uses some items to indicate the situation of direct reclaim in memory.stat，such as pgsteal and pgscan.
> > > I think there is no harm in adding another item to show the times of entering direct reclaim.
> > >
> >
> > Why do you consider this useful? Do you have a use case? If so,
> > please describe it in detail.
> >
> Since there are allocstall in proc/vmstat which indicate the number of
> entering direct reclaim of !cgroup_reclaim, So I think it maybe useful. For
> example, users could adjust memory.max to prevent entering direct reclaim
> through this item.So what do you think about it ?
We already do have events for that - have a look MEMCG_MAX. Can you work
with that?
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-06-23 8:01 [PATCH] mm/vmscan: add pgstall to memcg zhouchuyi
2022-06-24 20:42 ` Andrew Morton
2022-07-12 9:28 ` Chuyi Zhou
2022-07-12 13:55 ` Michal Hocko
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