diff mbox series

[v8,4/6] mm: memcg: add per-memcg zswap writeback stat

Message ID 20231130194023.4102148-5-nphamcs@gmail.com
State Superseded
Headers show
Series workload-specific and memory pressure-driven zswap writeback | expand

Commit Message

Nhat Pham Nov. 30, 2023, 7:40 p.m. UTC 
From: Domenico Cerasuolo <cerasuolodomenico@gmail.com>

Since zswap now writes back pages from memcg-specific LRUs, we now need a
new stat to show writebacks count for each memcg.

Suggested-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
---
 include/linux/vm_event_item.h | 1 +
 mm/memcontrol.c               | 1 +
 mm/vmstat.c                   | 1 +
 mm/zswap.c                    | 4 ++++
 4 files changed, 7 insertions(+)

Comments

Yosry Ahmed Dec. 5, 2023, 6:21 p.m. UTC | #1 
On Thu, Nov 30, 2023 at 11:40 AM Nhat Pham <nphamcs@gmail.com> wrote:
>
> From: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
>
> Since zswap now writes back pages from memcg-specific LRUs, we now need a
> new stat to show writebacks count for each memcg.
>
> Suggested-by: Nhat Pham <nphamcs@gmail.com>
> Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
> Signed-off-by: Nhat Pham <nphamcs@gmail.com>
> ---
>  include/linux/vm_event_item.h | 1 +
>  mm/memcontrol.c               | 1 +
>  mm/vmstat.c                   | 1 +
>  mm/zswap.c                    | 4 ++++
>  4 files changed, 7 insertions(+)
>
> diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> index d1b847502f09..f4569ad98edf 100644
> --- a/include/linux/vm_event_item.h
> +++ b/include/linux/vm_event_item.h
> @@ -142,6 +142,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
>  #ifdef CONFIG_ZSWAP
>                 ZSWPIN,
>                 ZSWPOUT,
> +               ZSWP_WB,

I think you dismissed Johannes's comment from v7 about ZSWPWB and
"zswpwb" being more consistent with the existing events.

>  #endif
>  #ifdef CONFIG_X86
>                 DIRECT_MAP_LEVEL2_SPLIT,
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 792ca21c5815..21d79249c8b4 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -703,6 +703,7 @@ static const unsigned int memcg_vm_event_stat[] = {
>  #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
>         ZSWPIN,
>         ZSWPOUT,
> +       ZSWP_WB,
>  #endif
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>         THP_FAULT_ALLOC,
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index afa5a38fcc9c..2249f85e4a87 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1401,6 +1401,7 @@ const char * const vmstat_text[] = {
>  #ifdef CONFIG_ZSWAP
>         "zswpin",
>         "zswpout",
> +       "zswp_wb",
>  #endif
>  #ifdef CONFIG_X86
>         "direct_map_level2_splits",
> diff --git a/mm/zswap.c b/mm/zswap.c
> index f323e45cbdc7..49b79393e472 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -760,6 +760,10 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
>         }
>         zswap_written_back_pages++;
>
> +       if (entry->objcg)
> +               count_objcg_event(entry->objcg, ZSWP_WB);
> +
> +       count_vm_event(ZSWP_WB);
>         /*
>          * Writeback started successfully, the page now belongs to the
>          * swapcache. Drop the entry from zswap - unless invalidate already
> --
> 2.34.1
Nhat Pham Dec. 5, 2023, 6:56 p.m. UTC | #2 
On Tue, Dec 5, 2023 at 10:22 AM Yosry Ahmed <yosryahmed@google.com> wrote:
>
> On Thu, Nov 30, 2023 at 11:40 AM Nhat Pham <nphamcs@gmail.com> wrote:
> >
> > From: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
> >
> > Since zswap now writes back pages from memcg-specific LRUs, we now need a
> > new stat to show writebacks count for each memcg.
> >
> > Suggested-by: Nhat Pham <nphamcs@gmail.com>
> > Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
> > Signed-off-by: Nhat Pham <nphamcs@gmail.com>
> > ---
> >  include/linux/vm_event_item.h | 1 +
> >  mm/memcontrol.c               | 1 +
> >  mm/vmstat.c                   | 1 +
> >  mm/zswap.c                    | 4 ++++
> >  4 files changed, 7 insertions(+)
> >
> > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> > index d1b847502f09..f4569ad98edf 100644
> > --- a/include/linux/vm_event_item.h
> > +++ b/include/linux/vm_event_item.h
> > @@ -142,6 +142,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
> >  #ifdef CONFIG_ZSWAP
> >                 ZSWPIN,
> >                 ZSWPOUT,
> > +               ZSWP_WB,
>
> I think you dismissed Johannes's comment from v7 about ZSWPWB and
> "zswpwb" being more consistent with the existing events.

I missed that entirely. Oops. Yeah I prefer ZSWPWB too. Let me send a fix.

>
> >  #endif
> >  #ifdef CONFIG_X86
> >                 DIRECT_MAP_LEVEL2_SPLIT,
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 792ca21c5815..21d79249c8b4 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -703,6 +703,7 @@ static const unsigned int memcg_vm_event_stat[] = {
> >  #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
> >         ZSWPIN,
> >         ZSWPOUT,
> > +       ZSWP_WB,
> >  #endif
> >  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> >         THP_FAULT_ALLOC,
> > diff --git a/mm/vmstat.c b/mm/vmstat.c
> > index afa5a38fcc9c..2249f85e4a87 100644
> > --- a/mm/vmstat.c
> > +++ b/mm/vmstat.c
> > @@ -1401,6 +1401,7 @@ const char * const vmstat_text[] = {
> >  #ifdef CONFIG_ZSWAP
> >         "zswpin",
> >         "zswpout",
> > +       "zswp_wb",
> >  #endif
> >  #ifdef CONFIG_X86
> >         "direct_map_level2_splits",
> > diff --git a/mm/zswap.c b/mm/zswap.c
> > index f323e45cbdc7..49b79393e472 100644
> > --- a/mm/zswap.c
> > +++ b/mm/zswap.c
> > @@ -760,6 +760,10 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
> >         }
> >         zswap_written_back_pages++;
> >
> > +       if (entry->objcg)
> > +               count_objcg_event(entry->objcg, ZSWP_WB);
> > +
> > +       count_vm_event(ZSWP_WB);
> >         /*
> >          * Writeback started successfully, the page now belongs to the
> >          * swapcache. Drop the entry from zswap - unless invalidate already
> > --
> > 2.34.1
Yosry Ahmed Dec. 5, 2023, 8:05 p.m. UTC | #3 
On Tue, Dec 5, 2023 at 11:33 AM Nhat Pham <nphamcs@gmail.com> wrote:
>
> Rename ZSWP_WB to ZSWPWB to better match the existing counters naming
> scheme.
>
> Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Nhat Pham <nphamcs@gmail.com>

For the original patch + this fix:

Reviewed-by: Yosry Ahmed <yosryahmed@google.com>

> ---
>  include/linux/vm_event_item.h | 2 +-
>  mm/memcontrol.c               | 2 +-
>  mm/vmstat.c                   | 2 +-
>  mm/zswap.c                    | 4 ++--
>  4 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
> index f4569ad98edf..747943bc8cc2 100644
> --- a/include/linux/vm_event_item.h
> +++ b/include/linux/vm_event_item.h
> @@ -142,7 +142,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
>  #ifdef CONFIG_ZSWAP
>                 ZSWPIN,
>                 ZSWPOUT,
> -               ZSWP_WB,
> +               ZSWPWB,
>  #endif
>  #ifdef CONFIG_X86
>                 DIRECT_MAP_LEVEL2_SPLIT,
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 21d79249c8b4..0286b7d38832 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -703,7 +703,7 @@ static const unsigned int memcg_vm_event_stat[] = {
>  #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
>         ZSWPIN,
>         ZSWPOUT,
> -       ZSWP_WB,
> +       ZSWPWB,
>  #endif
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>         THP_FAULT_ALLOC,
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index 2249f85e4a87..cfd8d8256f8e 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1401,7 +1401,7 @@ const char * const vmstat_text[] = {
>  #ifdef CONFIG_ZSWAP
>         "zswpin",
>         "zswpout",
> -       "zswp_wb",
> +       "zswpwb",
>  #endif
>  #ifdef CONFIG_X86
>         "direct_map_level2_splits",
> diff --git a/mm/zswap.c b/mm/zswap.c
> index c65b8ccc6b72..0fb0945c0031 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -761,9 +761,9 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
>         zswap_written_back_pages++;
>
>         if (entry->objcg)
> -               count_objcg_event(entry->objcg, ZSWP_WB);
> +               count_objcg_event(entry->objcg, ZSWPWB);
>
> -       count_vm_event(ZSWP_WB);
> +       count_vm_event(ZSWPWB);
>         /*
>          * Writeback started successfully, the page now belongs to the
>          * swapcache. Drop the entry from zswap - unless invalidate already
> --
> 2.34.1
diff mbox series

Patch

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index d1b847502f09..f4569ad98edf 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -142,6 +142,7 @@  enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 #ifdef CONFIG_ZSWAP
 		ZSWPIN,
 		ZSWPOUT,
+		ZSWP_WB,
 #endif
 #ifdef CONFIG_X86
 		DIRECT_MAP_LEVEL2_SPLIT,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 792ca21c5815..21d79249c8b4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -703,6 +703,7 @@  static const unsigned int memcg_vm_event_stat[] = {
 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
 	ZSWPIN,
 	ZSWPOUT,
+	ZSWP_WB,
 #endif
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	THP_FAULT_ALLOC,
diff --git a/mm/vmstat.c b/mm/vmstat.c
index afa5a38fcc9c..2249f85e4a87 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1401,6 +1401,7 @@  const char * const vmstat_text[] = {
 #ifdef CONFIG_ZSWAP
 	"zswpin",
 	"zswpout",
+	"zswp_wb",
 #endif
 #ifdef CONFIG_X86
 	"direct_map_level2_splits",
diff --git a/mm/zswap.c b/mm/zswap.c
index f323e45cbdc7..49b79393e472 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -760,6 +760,10 @@  static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
 	}
 	zswap_written_back_pages++;
 
+	if (entry->objcg)
+		count_objcg_event(entry->objcg, ZSWP_WB);
+
+	count_vm_event(ZSWP_WB);
 	/*
 	 * Writeback started successfully, the page now belongs to the
 	 * swapcache. Drop the entry from zswap - unless invalidate already