diff mbox series

[RFC,6/9] mm/vmscan: add page demotion counter

Message ID 20201007161747.FE7288F0@viggo.jf.intel.com (mailing list archive)
State New, archived
Headers show
Series Migrate Pages in lieu of discard | expand

Commit Message

Dave Hansen Oct. 7, 2020, 4:17 p.m. UTC 
From: Yang Shi <yang.shi@linux.alibaba.com>

Account the number of demoted pages into reclaim_state->nr_demoted.

Add pgdemote_kswapd and pgdemote_direct VM counters showed in
/proc/vmstat.

[ daveh:
   - __count_vm_events() a bit, and made them look at the THP
     size directly rather than getting data from migrate_pages()
]

Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
---

 b/include/linux/vm_event_item.h |    2 ++
 b/mm/vmscan.c                   |    6 ++++++
 b/mm/vmstat.c                   |    2 ++
 3 files changed, 10 insertions(+)

Comments

Huang, Ying Oct. 19, 2020, 7:37 a.m. UTC | #1 
Dave Hansen <dave.hansen@linux.intel.com> writes:

> From: Yang Shi <yang.shi@linux.alibaba.com>
>
> Account the number of demoted pages into reclaim_state->nr_demoted.

It appears that you don't add "nr_demoted" into struct reclaim_state.

> Add pgdemote_kswapd and pgdemote_direct VM counters showed in
> /proc/vmstat.
>
> [ daveh:
>    - __count_vm_events() a bit, and made them look at the THP
>      size directly rather than getting data from migrate_pages()

It appears that we get the data from migrate_pages() now.

> ]
>
> Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Huang Ying <ying.huang@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: David Hildenbrand <david@redhat.com>
> ---
>
>  b/include/linux/vm_event_item.h |    2 ++
>  b/mm/vmscan.c                   |    6 ++++++
>  b/mm/vmstat.c                   |    2 ++
>  3 files changed, 10 insertions(+)
>
> diff -puN include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter include/linux/vm_event_item.h
> --- a/include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.171642439 -0700
> +++ b/include/linux/vm_event_item.h	2020-10-07 09:15:32.179642439 -0700
> @@ -33,6 +33,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
>  		PGREUSE,
>  		PGSTEAL_KSWAPD,
>  		PGSTEAL_DIRECT,
> +		PGDEMOTE_KSWAPD,
> +		PGDEMOTE_DIRECT,
>  		PGSCAN_KSWAPD,
>  		PGSCAN_DIRECT,
>  		PGSCAN_DIRECT_THROTTLE,
> diff -puN mm/vmscan.c~mm-vmscan-add-page-demotion-counter mm/vmscan.c
> --- a/mm/vmscan.c~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.173642439 -0700
> +++ b/mm/vmscan.c	2020-10-07 09:15:32.180642439 -0700
> @@ -147,6 +147,7 @@ struct scan_control {
>  		unsigned int immediate;
>  		unsigned int file_taken;
>  		unsigned int taken;
> +		unsigned int demoted;

It appears that this newly added field isn't used in the patch.

>  	} nr;
>  
>  	/* for recording the reclaimed slab by now */
> @@ -1134,6 +1135,11 @@ static unsigned int demote_page_list(str
>  			    target_nid, MIGRATE_ASYNC, MR_DEMOTION,
>  			    &nr_succeeded);
>  
> +	if (current_is_kswapd())
> +		__count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);
> +	else
> +		__count_vm_events(PGDEMOTE_DIRECT, nr_succeeded);
> +
>  	return nr_succeeded;
>  }
>  
> diff -puN mm/vmstat.c~mm-vmscan-add-page-demotion-counter mm/vmstat.c
> --- a/mm/vmstat.c~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.175642439 -0700
> +++ b/mm/vmstat.c	2020-10-07 09:15:32.181642439 -0700
> @@ -1244,6 +1244,8 @@ const char * const vmstat_text[] = {
>  	"pgreuse",
>  	"pgsteal_kswapd",
>  	"pgsteal_direct",
> +	"pgdemote_kswapd",
> +	"pgdemote_direct",
>  	"pgscan_kswapd",
>  	"pgscan_direct",
>  	"pgscan_direct_throttle",
> _

Best Regards,
Huang, Ying
Yang Shi Oct. 27, 2020, 4:41 p.m. UTC | #2 
On Mon, Oct 19, 2020 at 12:38 AM Huang, Ying <ying.huang@intel.com> wrote:
>
> Dave Hansen <dave.hansen@linux.intel.com> writes:
>
> > From: Yang Shi <yang.shi@linux.alibaba.com>
> >
> > Account the number of demoted pages into reclaim_state->nr_demoted.
>
> It appears that you don't add "nr_demoted" into struct reclaim_state.
>
> > Add pgdemote_kswapd and pgdemote_direct VM counters showed in
> > /proc/vmstat.
> >
> > [ daveh:
> >    - __count_vm_events() a bit, and made them look at the THP
> >      size directly rather than getting data from migrate_pages()
>
> It appears that we get the data from migrate_pages() now.
>
> > ]
> >
> > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
> > Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> > Cc: David Rientjes <rientjes@google.com>
> > Cc: Huang Ying <ying.huang@intel.com>
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > Cc: David Hildenbrand <david@redhat.com>
> > ---
> >
> >  b/include/linux/vm_event_item.h |    2 ++
> >  b/mm/vmscan.c                   |    6 ++++++
> >  b/mm/vmstat.c                   |    2 ++
> >  3 files changed, 10 insertions(+)
> >
> > diff -puN include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter include/linux/vm_event_item.h
> > --- a/include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter       2020-10-07 09:15:32.171642439 -0700
> > +++ b/include/linux/vm_event_item.h   2020-10-07 09:15:32.179642439 -0700
> > @@ -33,6 +33,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
> >               PGREUSE,
> >               PGSTEAL_KSWAPD,
> >               PGSTEAL_DIRECT,
> > +             PGDEMOTE_KSWAPD,
> > +             PGDEMOTE_DIRECT,
> >               PGSCAN_KSWAPD,
> >               PGSCAN_DIRECT,
> >               PGSCAN_DIRECT_THROTTLE,
> > diff -puN mm/vmscan.c~mm-vmscan-add-page-demotion-counter mm/vmscan.c
> > --- a/mm/vmscan.c~mm-vmscan-add-page-demotion-counter 2020-10-07 09:15:32.173642439 -0700
> > +++ b/mm/vmscan.c     2020-10-07 09:15:32.180642439 -0700
> > @@ -147,6 +147,7 @@ struct scan_control {
> >               unsigned int immediate;
> >               unsigned int file_taken;
> >               unsigned int taken;
> > +             unsigned int demoted;
>
> It appears that this newly added field isn't used in the patch.

My original patch tracked nr_demoted in reclaim_stat as well, but it
seems Dave dropped that part. If Dave thinks it is not necessary to
keep tracking nr_demoted in reclaim_stat, then that field should be
dropped.

>
> >       } nr;
> >
> >       /* for recording the reclaimed slab by now */
> > @@ -1134,6 +1135,11 @@ static unsigned int demote_page_list(str
> >                           target_nid, MIGRATE_ASYNC, MR_DEMOTION,
> >                           &nr_succeeded);
> >
> > +     if (current_is_kswapd())
> > +             __count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);
> > +     else
> > +             __count_vm_events(PGDEMOTE_DIRECT, nr_succeeded);
> > +
> >       return nr_succeeded;
> >  }
> >
> > diff -puN mm/vmstat.c~mm-vmscan-add-page-demotion-counter mm/vmstat.c
> > --- a/mm/vmstat.c~mm-vmscan-add-page-demotion-counter 2020-10-07 09:15:32.175642439 -0700
> > +++ b/mm/vmstat.c     2020-10-07 09:15:32.181642439 -0700
> > @@ -1244,6 +1244,8 @@ const char * const vmstat_text[] = {
> >       "pgreuse",
> >       "pgsteal_kswapd",
> >       "pgsteal_direct",
> > +     "pgdemote_kswapd",
> > +     "pgdemote_direct",
> >       "pgscan_kswapd",
> >       "pgscan_direct",
> >       "pgscan_direct_throttle",
> > _
>
> Best Regards,
> Huang, Ying
>
Huang, Ying Oct. 28, 2020, 1:25 a.m. UTC | #3 
Yang Shi <shy828301@gmail.com> writes:

> On Mon, Oct 19, 2020 at 12:38 AM Huang, Ying <ying.huang@intel.com> wrote:
>>
>> Dave Hansen <dave.hansen@linux.intel.com> writes:
>>
>> > From: Yang Shi <yang.shi@linux.alibaba.com>
>> >
>> > Account the number of demoted pages into reclaim_state->nr_demoted.
>>
>> It appears that you don't add "nr_demoted" into struct reclaim_state.
>>
>> > Add pgdemote_kswapd and pgdemote_direct VM counters showed in
>> > /proc/vmstat.
>> >
>> > [ daveh:
>> >    - __count_vm_events() a bit, and made them look at the THP
>> >      size directly rather than getting data from migrate_pages()
>>
>> It appears that we get the data from migrate_pages() now.
>>
>> > ]
>> >
>> > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
>> > Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
>> > Cc: David Rientjes <rientjes@google.com>
>> > Cc: Huang Ying <ying.huang@intel.com>
>> > Cc: Dan Williams <dan.j.williams@intel.com>
>> > Cc: David Hildenbrand <david@redhat.com>
>> > ---
>> >
>> >  b/include/linux/vm_event_item.h |    2 ++
>> >  b/mm/vmscan.c                   |    6 ++++++
>> >  b/mm/vmstat.c                   |    2 ++
>> >  3 files changed, 10 insertions(+)
>> >
>> > diff -puN include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter include/linux/vm_event_item.h
>> > --- a/include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter       2020-10-07 09:15:32.171642439 -0700
>> > +++ b/include/linux/vm_event_item.h   2020-10-07 09:15:32.179642439 -0700
>> > @@ -33,6 +33,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
>> >               PGREUSE,
>> >               PGSTEAL_KSWAPD,
>> >               PGSTEAL_DIRECT,
>> > +             PGDEMOTE_KSWAPD,
>> > +             PGDEMOTE_DIRECT,
>> >               PGSCAN_KSWAPD,
>> >               PGSCAN_DIRECT,
>> >               PGSCAN_DIRECT_THROTTLE,
>> > diff -puN mm/vmscan.c~mm-vmscan-add-page-demotion-counter mm/vmscan.c
>> > --- a/mm/vmscan.c~mm-vmscan-add-page-demotion-counter 2020-10-07 09:15:32.173642439 -0700
>> > +++ b/mm/vmscan.c     2020-10-07 09:15:32.180642439 -0700
>> > @@ -147,6 +147,7 @@ struct scan_control {
>> >               unsigned int immediate;
>> >               unsigned int file_taken;
>> >               unsigned int taken;
>> > +             unsigned int demoted;
>>
>> It appears that this newly added field isn't used in the patch.
>
> My original patch tracked nr_demoted in reclaim_stat as well, but it
> seems Dave dropped that part. If Dave thinks it is not necessary to
> keep tracking nr_demoted in reclaim_stat, then that field should be
> dropped.

Personally, I prefer to collect nr_demoted in struct reclaim_stat and
call counting functions in shrink_inactive_list() as other reclaiming
statistics.

Best Regards,
Huang, Ying

>>
>> >       } nr;
>> >
>> >       /* for recording the reclaimed slab by now */
>> > @@ -1134,6 +1135,11 @@ static unsigned int demote_page_list(str
>> >                           target_nid, MIGRATE_ASYNC, MR_DEMOTION,
>> >                           &nr_succeeded);
>> >
>> > +     if (current_is_kswapd())
>> > +             __count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);
>> > +     else
>> > +             __count_vm_events(PGDEMOTE_DIRECT, nr_succeeded);
>> > +
>> >       return nr_succeeded;
>> >  }
>> >
>> > diff -puN mm/vmstat.c~mm-vmscan-add-page-demotion-counter mm/vmstat.c
>> > --- a/mm/vmstat.c~mm-vmscan-add-page-demotion-counter 2020-10-07 09:15:32.175642439 -0700
>> > +++ b/mm/vmstat.c     2020-10-07 09:15:32.181642439 -0700
>> > @@ -1244,6 +1244,8 @@ const char * const vmstat_text[] = {
>> >       "pgreuse",
>> >       "pgsteal_kswapd",
>> >       "pgsteal_direct",
>> > +     "pgdemote_kswapd",
>> > +     "pgdemote_direct",
>> >       "pgscan_kswapd",
>> >       "pgscan_direct",
>> >       "pgscan_direct_throttle",
>> > _
>>
>> Best Regards,
>> Huang, Ying
>>
diff mbox series

Patch

diff -puN include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter include/linux/vm_event_item.h
--- a/include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.171642439 -0700
+++ b/include/linux/vm_event_item.h	2020-10-07 09:15:32.179642439 -0700
@@ -33,6 +33,8 @@  enum vm_event_item { PGPGIN, PGPGOUT, PS
 		PGREUSE,
 		PGSTEAL_KSWAPD,
 		PGSTEAL_DIRECT,
+		PGDEMOTE_KSWAPD,
+		PGDEMOTE_DIRECT,
 		PGSCAN_KSWAPD,
 		PGSCAN_DIRECT,
 		PGSCAN_DIRECT_THROTTLE,
diff -puN mm/vmscan.c~mm-vmscan-add-page-demotion-counter mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.173642439 -0700
+++ b/mm/vmscan.c	2020-10-07 09:15:32.180642439 -0700
@@ -147,6 +147,7 @@  struct scan_control {
 		unsigned int immediate;
 		unsigned int file_taken;
 		unsigned int taken;
+		unsigned int demoted;
 	} nr;
 
 	/* for recording the reclaimed slab by now */
@@ -1134,6 +1135,11 @@  static unsigned int demote_page_list(str
 			    target_nid, MIGRATE_ASYNC, MR_DEMOTION,
 			    &nr_succeeded);
 
+	if (current_is_kswapd())
+		__count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);
+	else
+		__count_vm_events(PGDEMOTE_DIRECT, nr_succeeded);
+
 	return nr_succeeded;
 }
 
diff -puN mm/vmstat.c~mm-vmscan-add-page-demotion-counter mm/vmstat.c
--- a/mm/vmstat.c~mm-vmscan-add-page-demotion-counter	2020-10-07 09:15:32.175642439 -0700
+++ b/mm/vmstat.c	2020-10-07 09:15:32.181642439 -0700
@@ -1244,6 +1244,8 @@  const char * const vmstat_text[] = {
 	"pgreuse",
 	"pgsteal_kswapd",
 	"pgsteal_direct",
+	"pgdemote_kswapd",
+	"pgdemote_direct",
 	"pgscan_kswapd",
 	"pgscan_direct",
 	"pgscan_direct_throttle",