linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
* [PATCH -mm] memcg: fix handling of shmem migration
@ 2008-09-17  4:31 Daisuke Nishimura
  2008-09-17  5:46 ` KAMEZAWA Hiroyuki
  0 siblings, 1 reply; 12+ messages in thread
From: Daisuke Nishimura @ 2008-09-17  4:31 UTC (permalink / raw)
  To: linux-kernel, linux-mm; +Cc: akpm, balbir, kamezawa.hiroyu, xemul, nishimura

PG_swapbacked flag of newpage should be set(if needed) before
mem_cgroup_prepare_migration, because mem_cgroup_charge_common
checks the flag and determines whether it sets PAGE_CGROUP_FLAG_FILE or not.

Before this patch, if migrating shmem/tmpfs pages, newpage would be
charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
without the flag.

The problem here is mem_cgroup_move_lists doesn't clear(or set)
the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
another lru(anon) by mem_cgroup_move_lists. And this leads to
incorrect MEM_CGROUP_ZSTAT.
(In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
As a result, mem_cgroup_calc_reclaim returns very huge number and
causes soft lockup on page reclaim.)

I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
or not(I suppose it should be used to move between active <-> inactive,
not anon <-> file), I moved SetPageSwapBacked(newpage) before
mem_cgroup_prepare_migration.


Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
---
 mm/migrate.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 577d481..7343463 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -586,8 +586,6 @@ static int move_to_new_page(struct page *newpage, struct page *page)
 	/* Prepare mapping for the new page.*/
 	newpage->index = page->index;
 	newpage->mapping = page->mapping;
-	if (PageSwapBacked(page))
-		SetPageSwapBacked(newpage);
 
 	mapping = page_mapping(page);
 	if (!mapping)
@@ -636,6 +634,8 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 		goto move_newpage;
 	}
 
+	if (PageSwapBacked(page))
+		SetPageSwapBacked(newpage);
 	charge = mem_cgroup_prepare_migration(page, newpage);
 	if (charge == -ENOMEM) {
 		rc = -ENOMEM;

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration
  2008-09-17  4:31 [PATCH -mm] memcg: fix handling of shmem migration Daisuke Nishimura
@ 2008-09-17  5:46 ` KAMEZAWA Hiroyuki
  2008-09-17  5:50   ` KAMEZAWA Hiroyuki
  0 siblings, 1 reply; 12+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-09-17  5:46 UTC (permalink / raw)
  To: Daisuke Nishimura; +Cc: linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 13:31:49 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> PG_swapbacked flag of newpage should be set(if needed) before
> mem_cgroup_prepare_migration, because mem_cgroup_charge_common
> checks the flag and determines whether it sets PAGE_CGROUP_FLAG_FILE or not.
> 
> Before this patch, if migrating shmem/tmpfs pages, newpage would be
> charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> without the flag.
> 
Nice catch !
Thank you. 

Hmm, should I add MEM_CGROUP_CHARGE_TYPE_SHMEM rather than
setting flag to newpage ?

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>


> The problem here is mem_cgroup_move_lists doesn't clear(or set)
> the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
> remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
> another lru(anon) by mem_cgroup_move_lists. And this leads to
> incorrect MEM_CGROUP_ZSTAT.
> (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
> As a result, mem_cgroup_calc_reclaim returns very huge number and
> causes soft lockup on page reclaim.)
> 
> I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
> or not(I suppose it should be used to move between active <-> inactive,
> not anon <-> file), I moved SetPageSwapBacked(newpage) before
> mem_cgroup_prepare_migration.
> 
> 
> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
> ---
>  mm/migrate.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 577d481..7343463 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -586,8 +586,6 @@ static int move_to_new_page(struct page *newpage, struct page *page)
>  	/* Prepare mapping for the new page.*/
>  	newpage->index = page->index;
>  	newpage->mapping = page->mapping;
> -	if (PageSwapBacked(page))
> -		SetPageSwapBacked(newpage);
>  
>  	mapping = page_mapping(page);
>  	if (!mapping)
> @@ -636,6 +634,8 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
>  		goto move_newpage;
>  	}
>  
> +	if (PageSwapBacked(page))
> +		SetPageSwapBacked(newpage);
>  	charge = mem_cgroup_prepare_migration(page, newpage);
>  	if (charge == -ENOMEM) {
>  		rc = -ENOMEM;
> 

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration
  2008-09-17  5:46 ` KAMEZAWA Hiroyuki
@ 2008-09-17  5:50   ` KAMEZAWA Hiroyuki
  2008-09-17  6:19     ` Daisuke Nishimura
  0 siblings, 1 reply; 12+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-09-17  5:50 UTC (permalink / raw)
  To: KAMEZAWA Hiroyuki
  Cc: Daisuke Nishimura, linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 14:46:59 +0900
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:

> On Wed, 17 Sep 2008 13:31:49 +0900
> Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> 
> > PG_swapbacked flag of newpage should be set(if needed) before
> > mem_cgroup_prepare_migration, because mem_cgroup_charge_common
> > checks the flag and determines whether it sets PAGE_CGROUP_FLAG_FILE or not.
> > 
> > Before this patch, if migrating shmem/tmpfs pages, newpage would be
> > charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> > without the flag.
> > 
> Nice catch !
> Thank you. 
> 
> Hmm, should I add MEM_CGROUP_CHARGE_TYPE_SHMEM rather than
> setting flag to newpage ?
> 
> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> 
I acked but.. can't this change moved into memcontrol.c ?

Thanks,
-Kame

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration
  2008-09-17  5:50   ` KAMEZAWA Hiroyuki
@ 2008-09-17  6:19     ` Daisuke Nishimura
  2008-09-17  6:38       ` KAMEZAWA Hiroyuki
  0 siblings, 1 reply; 12+ messages in thread
From: Daisuke Nishimura @ 2008-09-17  6:19 UTC (permalink / raw)
  To: KAMEZAWA Hiroyuki; +Cc: nishimura, linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 14:50:03 +0900, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> On Wed, 17 Sep 2008 14:46:59 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> 
> > On Wed, 17 Sep 2008 13:31:49 +0900
> > Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> > 
> > > PG_swapbacked flag of newpage should be set(if needed) before
> > > mem_cgroup_prepare_migration, because mem_cgroup_charge_common
> > > checks the flag and determines whether it sets PAGE_CGROUP_FLAG_FILE or not.
> > > 
> > > Before this patch, if migrating shmem/tmpfs pages, newpage would be
> > > charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> > > without the flag.
> > > 
> > Nice catch !
> > Thank you. 
> > 
> > Hmm, should I add MEM_CGROUP_CHARGE_TYPE_SHMEM rather than
> > setting flag to newpage ?
> > 
> > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> > 
> I acked but.. can't this change moved into memcontrol.c ?
> 

Hmm, something like this?

---
@@ -734,6 +734,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpa
        if (mem_cgroup_subsys.disabled)
                return 0;

+       if (PageSwapBacked(page))
+               SetPageSwapBacked(newpage);
+
        lock_page_cgroup(page);
        pc = page_get_page_cgroup(page);
        if (pc) {
---

Or, adding MEM_CGROUP_CHARGE_TYPE_SHMEM and

---
@@ -740,7 +740,10 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newp
                mem = pc->mem_cgroup;
                css_get(&mem->css);
                if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
-                       ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+                       if (page_is_file_cache(page))
+                               ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+                       else
+                               ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
        }
        unlock_page_cgroup(page);
        if (mem) {
---
(Of course, mem_cgroup_charge_common should be modified too.)


Thanks,
Daisuke Nishimura.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration
  2008-09-17  6:19     ` Daisuke Nishimura
@ 2008-09-17  6:38       ` KAMEZAWA Hiroyuki
  2008-09-17  6:45         ` Daisuke Nishimura
  0 siblings, 1 reply; 12+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-09-17  6:38 UTC (permalink / raw)
  To: Daisuke Nishimura; +Cc: linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 15:19:51 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> Hmm, something like this?
> 
> ---
> @@ -734,6 +734,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpa
>         if (mem_cgroup_subsys.disabled)
>                 return 0;
> 
> +       if (PageSwapBacked(page))
> +               SetPageSwapBacked(newpage);
> +
>         lock_page_cgroup(page);
>         pc = page_get_page_cgroup(page);
>         if (pc) {
> ---
> 
> Or, adding MEM_CGROUP_CHARGE_TYPE_SHMEM and
> 
> ---
> @@ -740,7 +740,10 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newp
>                 mem = pc->mem_cgroup;
>                 css_get(&mem->css);
>                 if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
> -                       ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> +                       if (page_is_file_cache(page))
> +                               ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> +                       else
> +                               ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
>         }
>         unlock_page_cgroup(page);
>         if (mem) {
> ---
> (Of course, mem_cgroup_charge_common should be modified too.)
> 
like this :) I don't want to change logic in migration.c
(and this is special case handling for memcg.)

Thanks,
-Kame

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration
  2008-09-17  6:38       ` KAMEZAWA Hiroyuki
@ 2008-09-17  6:45         ` Daisuke Nishimura
  2008-09-17  7:55           ` [PATCH -mm] memcg: fix handling of shmem migration(v2) Daisuke Nishimura
  0 siblings, 1 reply; 12+ messages in thread
From: Daisuke Nishimura @ 2008-09-17  6:45 UTC (permalink / raw)
  To: KAMEZAWA Hiroyuki; +Cc: nishimura, linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 15:38:26 +0900, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> On Wed, 17 Sep 2008 15:19:51 +0900
> Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> 
> > Hmm, something like this?
> > 
> > ---
> > @@ -734,6 +734,9 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpa
> >         if (mem_cgroup_subsys.disabled)
> >                 return 0;
> > 
> > +       if (PageSwapBacked(page))
> > +               SetPageSwapBacked(newpage);
> > +
> >         lock_page_cgroup(page);
> >         pc = page_get_page_cgroup(page);
> >         if (pc) {
> > ---
> > 
> > Or, adding MEM_CGROUP_CHARGE_TYPE_SHMEM and
> > 
> > ---
> > @@ -740,7 +740,10 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newp
> >                 mem = pc->mem_cgroup;
> >                 css_get(&mem->css);
> >                 if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
> > -                       ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +                       if (page_is_file_cache(page))
> > +                               ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +                       else
> > +                               ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
> >         }
> >         unlock_page_cgroup(page);
> >         if (mem) {
> > ---
> > (Of course, mem_cgroup_charge_common should be modified too.)
> > 
> like this :) I don't want to change logic in migration.c
> (and this is special case handling for memcg.)
> 
OK.
I'll rewrite and resend it later.

Thanks,
Daisuke Nishimura.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-17  6:45         ` Daisuke Nishimura
@ 2008-09-17  7:55           ` Daisuke Nishimura
  2008-09-17  9:18             ` KAMEZAWA Hiroyuki
  2008-09-17 22:51             ` Andrew Morton
  0 siblings, 2 replies; 12+ messages in thread
From: Daisuke Nishimura @ 2008-09-17  7:55 UTC (permalink / raw)
  To: KAMEZAWA Hiroyuki; +Cc: nishimura, linux-kernel, linux-mm, akpm, balbir, xemul

Before this patch, if migrating shmem/tmpfs pages, newpage would be
charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
without the flag.

The problem here is mem_cgroup_move_lists doesn't clear(or set)
the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
another lru(anon) by mem_cgroup_move_lists. And this leads to
incorrect MEM_CGROUP_ZSTAT.
(In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
As a result, mem_cgroup_calc_reclaim returns very huge number and
causes soft lockup on page reclaim.)

I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
or not(I suppose it should be used to move between active <-> inactive,
not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
at shmem's page migration.


ChangeLog: v1->v2
- instead of modifying migrate.c, modify memcontrol.c only.
- add MEM_CGROUP_CHARGE_TYPE_SHMEM.


Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
---
 mm/memcontrol.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2979d22..ef8812d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -179,6 +179,7 @@ enum charge_type {
 	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
 	MEM_CGROUP_CHARGE_TYPE_MAPPED,
 	MEM_CGROUP_CHARGE_TYPE_FORCE,	/* used by force_empty */
+	MEM_CGROUP_CHARGE_TYPE_SHMEM,	/* used by page migration of shmem */
 };
 
 /*
@@ -579,8 +580,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
 			pc->flags |= PAGE_CGROUP_FLAG_FILE;
 		else
 			pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
-	} else
+	} else if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
 		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
+	else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
+		pc->flags = PAGE_CGROUP_FLAG_CACHE | PAGE_CGROUP_FLAG_ACTIVE;
 
 	lock_page_cgroup(page);
 	if (unlikely(page_get_page_cgroup(page))) {
@@ -739,8 +742,12 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
 	if (pc) {
 		mem = pc->mem_cgroup;
 		css_get(&mem->css);
-		if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
-			ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+		if (pc->flags & PAGE_CGROUP_FLAG_CACHE) {
+			if (page_is_file_cache(page))
+				ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
+			else
+				ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
+		}
 	}
 	unlock_page_cgroup(page);
 	if (mem) {

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-17  7:55           ` [PATCH -mm] memcg: fix handling of shmem migration(v2) Daisuke Nishimura
@ 2008-09-17  9:18             ` KAMEZAWA Hiroyuki
  2008-09-17 22:51             ` Andrew Morton
  1 sibling, 0 replies; 12+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-09-17  9:18 UTC (permalink / raw)
  To: Daisuke Nishimura; +Cc: linux-kernel, linux-mm, akpm, balbir, xemul

On Wed, 17 Sep 2008 16:55:44 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> Before this patch, if migrating shmem/tmpfs pages, newpage would be
> charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> without the flag.
> 
> The problem here is mem_cgroup_move_lists doesn't clear(or set)
> the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
> remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
> another lru(anon) by mem_cgroup_move_lists. And this leads to
> incorrect MEM_CGROUP_ZSTAT.
> (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
> As a result, mem_cgroup_calc_reclaim returns very huge number and
> causes soft lockup on page reclaim.)
> 
> I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
> or not(I suppose it should be used to move between active <-> inactive,
> not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
> at shmem's page migration.
> 
> 
> ChangeLog: v1->v2
> - instead of modifying migrate.c, modify memcontrol.c only.
> - add MEM_CGROUP_CHARGE_TYPE_SHMEM.
> 
I'll fix mem_cgroup_charge_cache_page() to use TYPE_SHMEM later.
Thank you.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>


--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-17  7:55           ` [PATCH -mm] memcg: fix handling of shmem migration(v2) Daisuke Nishimura
  2008-09-17  9:18             ` KAMEZAWA Hiroyuki
@ 2008-09-17 22:51             ` Andrew Morton
  2008-09-18  2:03               ` Daisuke Nishimura
  2008-09-18  2:38               ` KAMEZAWA Hiroyuki
  1 sibling, 2 replies; 12+ messages in thread
From: Andrew Morton @ 2008-09-17 22:51 UTC (permalink / raw)
  To: Daisuke Nishimura; +Cc: kamezawa.hiroyu, linux-kernel, linux-mm, balbir, xemul

On Wed, 17 Sep 2008 16:55:44 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:

> Before this patch, if migrating shmem/tmpfs pages, newpage would be
> charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> without the flag.
> 
> The problem here is mem_cgroup_move_lists doesn't clear(or set)
> the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
> remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
> another lru(anon) by mem_cgroup_move_lists. And this leads to
> incorrect MEM_CGROUP_ZSTAT.
> (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
> As a result, mem_cgroup_calc_reclaim returns very huge number and
> causes soft lockup on page reclaim.)
> 
> I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
> or not(I suppose it should be used to move between active <-> inactive,
> not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
> at shmem's page migration.
> 
> 
> ChangeLog: v1->v2
> - instead of modifying migrate.c, modify memcontrol.c only.
> - add MEM_CGROUP_CHARGE_TYPE_SHMEM.
> 
> 
> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
> ---
>  mm/memcontrol.c |   13 ++++++++++---
>  1 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 2979d22..ef8812d 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -179,6 +179,7 @@ enum charge_type {
>  	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
>  	MEM_CGROUP_CHARGE_TYPE_MAPPED,
>  	MEM_CGROUP_CHARGE_TYPE_FORCE,	/* used by force_empty */
> +	MEM_CGROUP_CHARGE_TYPE_SHMEM,	/* used by page migration of shmem */
>  };
>  
>  /*
> @@ -579,8 +580,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
>  			pc->flags |= PAGE_CGROUP_FLAG_FILE;
>  		else
>  			pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
> -	} else
> +	} else if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
>  		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
> +	else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
> +		pc->flags = PAGE_CGROUP_FLAG_CACHE | PAGE_CGROUP_FLAG_ACTIVE;
>  
>  	lock_page_cgroup(page);
>  	if (unlikely(page_get_page_cgroup(page))) {
> @@ -739,8 +742,12 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
>  	if (pc) {
>  		mem = pc->mem_cgroup;
>  		css_get(&mem->css);
> -		if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
> -			ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> +		if (pc->flags & PAGE_CGROUP_FLAG_CACHE) {
> +			if (page_is_file_cache(page))
> +				ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> +			else
> +				ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
> +		}
>  	}
>  	unlock_page_cgroup(page);
>  	if (mem) {

I queued this as a fix against
vmscan-split-lru-lists-into-anon-file-sets.patch.  Was that appropriate?

If the bug you're fixing here is also present in mainline then I'll
need to ask for a tested patch against mainline, please.



--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-17 22:51             ` Andrew Morton
@ 2008-09-18  2:03               ` Daisuke Nishimura
  2008-09-18  2:38               ` KAMEZAWA Hiroyuki
  1 sibling, 0 replies; 12+ messages in thread
From: Daisuke Nishimura @ 2008-09-18  2:03 UTC (permalink / raw)
  To: Andrew Morton
  Cc: nishimura, kamezawa.hiroyu, linux-kernel, linux-mm, balbir, xemul

On Wed, 17 Sep 2008 15:51:12 -0700, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Wed, 17 Sep 2008 16:55:44 +0900
> Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> 
> > Before this patch, if migrating shmem/tmpfs pages, newpage would be
> > charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> > without the flag.
> > 
> > The problem here is mem_cgroup_move_lists doesn't clear(or set)
> > the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
> > remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
> > another lru(anon) by mem_cgroup_move_lists. And this leads to
> > incorrect MEM_CGROUP_ZSTAT.
> > (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
> > As a result, mem_cgroup_calc_reclaim returns very huge number and
> > causes soft lockup on page reclaim.)
> > 
> > I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
> > or not(I suppose it should be used to move between active <-> inactive,
> > not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
> > at shmem's page migration.
> > 
> > 
> > ChangeLog: v1->v2
> > - instead of modifying migrate.c, modify memcontrol.c only.
> > - add MEM_CGROUP_CHARGE_TYPE_SHMEM.
> > 
> > 
> > Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
> > ---
> >  mm/memcontrol.c |   13 ++++++++++---
> >  1 files changed, 10 insertions(+), 3 deletions(-)
> > 
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 2979d22..ef8812d 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -179,6 +179,7 @@ enum charge_type {
> >  	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
> >  	MEM_CGROUP_CHARGE_TYPE_MAPPED,
> >  	MEM_CGROUP_CHARGE_TYPE_FORCE,	/* used by force_empty */
> > +	MEM_CGROUP_CHARGE_TYPE_SHMEM,	/* used by page migration of shmem */
> >  };
> >  
> >  /*
> > @@ -579,8 +580,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
> >  			pc->flags |= PAGE_CGROUP_FLAG_FILE;
> >  		else
> >  			pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
> > -	} else
> > +	} else if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
> >  		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
> > +	else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
> > +		pc->flags = PAGE_CGROUP_FLAG_CACHE | PAGE_CGROUP_FLAG_ACTIVE;
> >  
> >  	lock_page_cgroup(page);
> >  	if (unlikely(page_get_page_cgroup(page))) {
> > @@ -739,8 +742,12 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
> >  	if (pc) {
> >  		mem = pc->mem_cgroup;
> >  		css_get(&mem->css);
> > -		if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
> > -			ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +		if (pc->flags & PAGE_CGROUP_FLAG_CACHE) {
> > +			if (page_is_file_cache(page))
> > +				ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +			else
> > +				ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
> > +		}
> >  	}
> >  	unlock_page_cgroup(page);
> >  	if (mem) {
> 
> I queued this as a fix against
> vmscan-split-lru-lists-into-anon-file-sets.patch.  Was that appropriate?
> 
Yes, thanks.

> If the bug you're fixing here is also present in mainline then I'll
> need to ask for a tested patch against mainline, please.
> 
I don't think this bug exist in mainline, where memcg have
only two ZSTAT(active/inactive) and mem_cgroup_move_lists can handle
them properly.


Thanks,
Daisuke Nishimura.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-17 22:51             ` Andrew Morton
  2008-09-18  2:03               ` Daisuke Nishimura
@ 2008-09-18  2:38               ` KAMEZAWA Hiroyuki
  2008-09-18  5:43                 ` Balbir Singh
  1 sibling, 1 reply; 12+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-09-18  2:38 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Daisuke Nishimura, linux-kernel, linux-mm, balbir, xemul

On Wed, 17 Sep 2008 15:51:12 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Wed, 17 Sep 2008 16:55:44 +0900
> Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> 
> > Before this patch, if migrating shmem/tmpfs pages, newpage would be
> > charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
> > without the flag.
> > 
> > The problem here is mem_cgroup_move_lists doesn't clear(or set)
> > the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
> > remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
> > another lru(anon) by mem_cgroup_move_lists. And this leads to
> > incorrect MEM_CGROUP_ZSTAT.
> > (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
> > As a result, mem_cgroup_calc_reclaim returns very huge number and
> > causes soft lockup on page reclaim.)
> > 
> > I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
> > or not(I suppose it should be used to move between active <-> inactive,
> > not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
> > at shmem's page migration.
> > 
> > 
> > ChangeLog: v1->v2
> > - instead of modifying migrate.c, modify memcontrol.c only.
> > - add MEM_CGROUP_CHARGE_TYPE_SHMEM.
> > 
> > 
> > Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
> > ---
> >  mm/memcontrol.c |   13 ++++++++++---
> >  1 files changed, 10 insertions(+), 3 deletions(-)
> > 
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index 2979d22..ef8812d 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -179,6 +179,7 @@ enum charge_type {
> >  	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
> >  	MEM_CGROUP_CHARGE_TYPE_MAPPED,
> >  	MEM_CGROUP_CHARGE_TYPE_FORCE,	/* used by force_empty */
> > +	MEM_CGROUP_CHARGE_TYPE_SHMEM,	/* used by page migration of shmem */
> >  };
> >  
> >  /*
> > @@ -579,8 +580,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
> >  			pc->flags |= PAGE_CGROUP_FLAG_FILE;
> >  		else
> >  			pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
> > -	} else
> > +	} else if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
> >  		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
> > +	else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
> > +		pc->flags = PAGE_CGROUP_FLAG_CACHE | PAGE_CGROUP_FLAG_ACTIVE;
> >  
> >  	lock_page_cgroup(page);
> >  	if (unlikely(page_get_page_cgroup(page))) {
> > @@ -739,8 +742,12 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
> >  	if (pc) {
> >  		mem = pc->mem_cgroup;
> >  		css_get(&mem->css);
> > -		if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
> > -			ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +		if (pc->flags & PAGE_CGROUP_FLAG_CACHE) {
> > +			if (page_is_file_cache(page))
> > +				ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > +			else
> > +				ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
> > +		}
> >  	}
> >  	unlock_page_cgroup(page);
> >  	if (mem) {
> 
> I queued this as a fix against
> vmscan-split-lru-lists-into-anon-file-sets.patch.  Was that appropriate?
> 
> If the bug you're fixing here is also present in mainline then I'll
> need to ask for a tested patch against mainline, please.
> 
I think this bug depends on split-lru patch set.
Mayne not in mainline yet...?

Thanks,
-Kame

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH -mm] memcg: fix handling of shmem migration(v2)
  2008-09-18  2:38               ` KAMEZAWA Hiroyuki
@ 2008-09-18  5:43                 ` Balbir Singh
  0 siblings, 0 replies; 12+ messages in thread
From: Balbir Singh @ 2008-09-18  5:43 UTC (permalink / raw)
  To: KAMEZAWA Hiroyuki
  Cc: Andrew Morton, Daisuke Nishimura, linux-kernel, linux-mm, xemul

KAMEZAWA Hiroyuki wrote:
> On Wed, 17 Sep 2008 15:51:12 -0700
> Andrew Morton <akpm@linux-foundation.org> wrote:
> 
>> On Wed, 17 Sep 2008 16:55:44 +0900
>> Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
>>
>>> Before this patch, if migrating shmem/tmpfs pages, newpage would be
>>> charged with PAGE_CGROUP_FLAG_FILE set, while oldpage has been charged
>>> without the flag.
>>>
>>> The problem here is mem_cgroup_move_lists doesn't clear(or set)
>>> the PAGE_CGROUP_FLAG_FILE flag, so pc->flags of the newpage
>>> remains PAGE_CGROUP_FLAG_FILE set even when the pc is moved to
>>> another lru(anon) by mem_cgroup_move_lists. And this leads to
>>> incorrect MEM_CGROUP_ZSTAT.
>>> (In my test, I see an underflow of MEM_CGROUP_ZSTAT(active_file).
>>> As a result, mem_cgroup_calc_reclaim returns very huge number and
>>> causes soft lockup on page reclaim.)
>>>
>>> I'm not sure if mem_cgroup_move_lists should handle PAGE_CGROUP_FLAG_FILE
>>> or not(I suppose it should be used to move between active <-> inactive,
>>> not anon <-> file), I added MEM_CGROUP_CHARGE_TYPE_SHMEM for precharge
>>> at shmem's page migration.
>>>
>>>
>>> ChangeLog: v1->v2
>>> - instead of modifying migrate.c, modify memcontrol.c only.
>>> - add MEM_CGROUP_CHARGE_TYPE_SHMEM.
>>>
>>>
>>> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
>>> ---
>>>  mm/memcontrol.c |   13 ++++++++++---
>>>  1 files changed, 10 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>>> index 2979d22..ef8812d 100644
>>> --- a/mm/memcontrol.c
>>> +++ b/mm/memcontrol.c
>>> @@ -179,6 +179,7 @@ enum charge_type {
>>>  	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
>>>  	MEM_CGROUP_CHARGE_TYPE_MAPPED,
>>>  	MEM_CGROUP_CHARGE_TYPE_FORCE,	/* used by force_empty */
>>> +	MEM_CGROUP_CHARGE_TYPE_SHMEM,	/* used by page migration of shmem */
>>>  };
>>>  
>>>  /*
>>> @@ -579,8 +580,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
>>>  			pc->flags |= PAGE_CGROUP_FLAG_FILE;
>>>  		else
>>>  			pc->flags |= PAGE_CGROUP_FLAG_ACTIVE;
>>> -	} else
>>> +	} else if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
>>>  		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
>>> +	else /* MEM_CGROUP_CHARGE_TYPE_SHMEM */
>>> +		pc->flags = PAGE_CGROUP_FLAG_CACHE | PAGE_CGROUP_FLAG_ACTIVE;
>>>  
>>>  	lock_page_cgroup(page);
>>>  	if (unlikely(page_get_page_cgroup(page))) {
>>> @@ -739,8 +742,12 @@ int mem_cgroup_prepare_migration(struct page *page, struct page *newpage)
>>>  	if (pc) {
>>>  		mem = pc->mem_cgroup;
>>>  		css_get(&mem->css);
>>> -		if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
>>> -			ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
>>> +		if (pc->flags & PAGE_CGROUP_FLAG_CACHE) {
>>> +			if (page_is_file_cache(page))
>>> +				ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
>>> +			else
>>> +				ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
>>> +		}
>>>  	}
>>>  	unlock_page_cgroup(page);
>>>  	if (mem) {
>> I queued this as a fix against
>> vmscan-split-lru-lists-into-anon-file-sets.patch.  Was that appropriate?
>>
>> If the bug you're fixing here is also present in mainline then I'll
>> need to ask for a tested patch against mainline, please.
>>
> I think this bug depends on split-lru patch set.
> Mayne not in mainline yet...?

Yes, that sounds correct to me, this should be a -mm only patch.

-- 
	Balbir

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2008-09-18  5:44 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-09-17  4:31 [PATCH -mm] memcg: fix handling of shmem migration Daisuke Nishimura
2008-09-17  5:46 ` KAMEZAWA Hiroyuki
2008-09-17  5:50   ` KAMEZAWA Hiroyuki
2008-09-17  6:19     ` Daisuke Nishimura
2008-09-17  6:38       ` KAMEZAWA Hiroyuki
2008-09-17  6:45         ` Daisuke Nishimura
2008-09-17  7:55           ` [PATCH -mm] memcg: fix handling of shmem migration(v2) Daisuke Nishimura
2008-09-17  9:18             ` KAMEZAWA Hiroyuki
2008-09-17 22:51             ` Andrew Morton
2008-09-18  2:03               ` Daisuke Nishimura
2008-09-18  2:38               ` KAMEZAWA Hiroyuki
2008-09-18  5:43                 ` Balbir Singh

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox