diff mbox series

[v7,4/6] mm: memcg: add per-memcg zswap writeback stat

Message ID 20231127234600.2971029-5-nphamcs@gmail.com
State New
Headers
Series workload-specific and memory pressure-driven zswap writeback |

Commit Message

Nhat Pham Nov. 27, 2023, 11:45 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                    | 3 +++
 4 files changed, 6 insertions(+)

Comments

Johannes Weiner Nov. 29, 2023, 3:25 p.m. UTC | #1 
On Mon, Nov 27, 2023 at 03:45:58PM -0800, Nhat Pham 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                    | 3 +++
>  4 files changed, 6 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,
>  #endif
>  #ifdef CONFIG_X86
>  		DIRECT_MAP_LEVEL2_SPLIT,
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 8c0f3f971179..f88c8fd03689 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",

ZSWPWB and "zswpwb" would match the existing naming scheme a bit
better.

>  #endif
>  #ifdef CONFIG_X86
>  	"direct_map_level2_splits",
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 5e397fc1f375..6a761753f979 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -754,6 +754,9 @@ 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);
> +

You need to call count_vm_event() as well, otherwise the /proc/vmstat
counter will stay zero.
Nhat Pham Nov. 30, 2023, 1:26 a.m. UTC | #2 
On Wed, Nov 29, 2023 at 7:25 AM Johannes Weiner <hannes@cmpxchg.org> wrote:
>
> On Mon, Nov 27, 2023 at 03:45:58PM -0800, Nhat Pham 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                    | 3 +++
> >  4 files changed, 6 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,
> >  #endif
> >  #ifdef CONFIG_X86
> >               DIRECT_MAP_LEVEL2_SPLIT,
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 8c0f3f971179..f88c8fd03689 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",
>
> ZSWPWB and "zswpwb" would match the existing naming scheme a bit
> better.
>
> >  #endif
> >  #ifdef CONFIG_X86
> >       "direct_map_level2_splits",
> > diff --git a/mm/zswap.c b/mm/zswap.c
> > index 5e397fc1f375..6a761753f979 100644
> > --- a/mm/zswap.c
> > +++ b/mm/zswap.c
> > @@ -754,6 +754,9 @@ 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);
> > +
>
> You need to call count_vm_event() as well, otherwise the /proc/vmstat
> counter will stay zero.

Ahh I didn't check that. I only looked at the cgroup's memory.stat
counter. I'll fix this for v8!
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 8c0f3f971179..f88c8fd03689 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 5e397fc1f375..6a761753f979 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -754,6 +754,9 @@  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);
+
 	/*
 	 * Writeback started successfully, the page now belongs to the
 	 * swapcache. Drop the entry from zswap - unless invalidate already