[PATCH RESEND 1/4] memcg: mark init_section_page_cgroup() properly

[PATCH RESEND 1/4] memcg: mark init_section_page_cgroup() properly

[Namhyung Kim]

The commit ca371c0d7e23 ("memcg: fix page_cgroup fatal error
in FLATMEM") removes call to alloc_bootmem() in the function
so that it can be marked as __meminit to reduce memory usage
when MEMORY_HOTPLUG=n.

Also as new helper function alloc_page_cgroup() is called only
in the function, it should be marked too.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
---
I kept Acked-by's because it seemed like a trivial change, no?

 mm/page_cgroup.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 99055010cece..81205c52735c 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -130,7 +130,7 @@ struct page *lookup_cgroup_page(struct page_cgroup *pc)
 	return page;
 }
 
-static void *__init_refok alloc_page_cgroup(size_t size, int nid)
+static void *__meminit alloc_page_cgroup(size_t size, int nid)
 {
 	void *addr = NULL;
 
@@ -162,7 +162,7 @@ static void free_page_cgroup(void *addr)
 }
 #endif
 
-static int __init_refok init_section_page_cgroup(unsigned long pfn)
+static int __meminit init_section_page_cgroup(unsigned long pfn)
 {
 	struct page_cgroup *base, *pc;
 	struct mem_section *section;
-- 
1.7.4

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

[PATCH RESEND 2/4] memcg: fix off-by-one when calculating swap cgroup map length

[Namhyung Kim]

It allocated one more page than necessary if @max_pages was
a multiple of SC_PER_PAGE.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---
 mm/page_cgroup.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 81205c52735c..e7208105203c 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -475,7 +475,7 @@ int swap_cgroup_swapon(int type, unsigned long max_pages)
 	if (!do_swap_account)
 		return 0;
 
-	length = ((max_pages/SC_PER_PAGE) + 1);
+	length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
 	array_size = length * sizeof(void *);
 
 	array = vmalloc(array_size);
-- 
1.7.4

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

[PATCH RESEND 3/4] memcg: move page-freeing code out of lock

[Namhyung Kim]

Move page-freeing code out of swap_cgroup_mutex in the hope that it
could reduce few of theoretical contentions between swapons and/or
swapoffs.

This is just a cleanup, no functional changes.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
---
 mm/page_cgroup.c |   22 +++++++++++++---------
 1 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index e7208105203c..9223bb48e80f 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -492,8 +492,8 @@ int swap_cgroup_swapon(int type, unsigned long max_pages)
 		/* memory shortage */
 		ctrl->map = NULL;
 		ctrl->length = 0;
-		vfree(array);
 		mutex_unlock(&swap_cgroup_mutex);
+		vfree(array);
 		goto nomem;
 	}
 	mutex_unlock(&swap_cgroup_mutex);
@@ -508,7 +508,8 @@ nomem:
 
 void swap_cgroup_swapoff(int type)
 {
-	int i;
+	struct page **map;
+	unsigned long i, length;
 	struct swap_cgroup_ctrl *ctrl;
 
 	if (!do_swap_account)
@@ -516,17 +517,20 @@ void swap_cgroup_swapoff(int type)
 
 	mutex_lock(&swap_cgroup_mutex);
 	ctrl = &swap_cgroup_ctrl[type];
-	if (ctrl->map) {
-		for (i = 0; i < ctrl->length; i++) {
-			struct page *page = ctrl->map[i];
+	map = ctrl->map;
+	length = ctrl->length;
+	ctrl->map = NULL;
+	ctrl->length = 0;
+	mutex_unlock(&swap_cgroup_mutex);
+
+	if (map) {
+		for (i = 0; i < length; i++) {
+			struct page *page = map[i];
 			if (page)
 				__free_page(page);
 		}
-		vfree(ctrl->map);
-		ctrl->map = NULL;
-		ctrl->length = 0;
+		vfree(map);
 	}
-	mutex_unlock(&swap_cgroup_mutex);
 }
 
 #endif
-- 
1.7.4

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

[PATCH RESEND 4/4] MAINTAINERS: add mm/page_cgroup.c into memcg subsystem

[Namhyung Kim]

AFAICS mm/page_cgroup.c is for memcg subsystem, but it was directed
only to generic cgroup maintainers. Fix it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
---
 MAINTAINERS |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 649600cb8ec9..1a369aa9a578 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4121,6 +4121,7 @@ M:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
 L:	linux-mm@kvack.org
 S:	Maintained
 F:	mm/memcontrol.c
+F:	mm/page_cgroup.c
 
 MEMORY TECHNOLOGY DEVICES (MTD)
 M:	David Woodhouse <dwmw2@infradead.org>
-- 
1.7.4

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH RESEND 1/4] memcg: mark init_section_page_cgroup() properly

[Michal Hocko]

On Tue 12-04-11 11:35:34, Namhyung Kim wrote:
> The commit ca371c0d7e23 ("memcg: fix page_cgroup fatal error
> in FLATMEM") removes call to alloc_bootmem() in the function
> so that it can be marked as __meminit to reduce memory usage
> when MEMORY_HOTPLUG=n.
> 
> Also as new helper function alloc_page_cgroup() is called only
> in the function, it should be marked too.
> 
> Signed-off-by: Namhyung Kim <namhyung@gmail.com>
> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> Cc: Michal Hocko <mhocko@suse.cz>

I am not aware I would be involved in the first round, but yes this
looks correct and reasonable. You can add my
Reviewed-by: Michal Hocko <mhocko@suse.cz>
if you care.

> ---
> I kept Acked-by's because it seemed like a trivial change, no?
> 
>  mm/page_cgroup.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
> index 99055010cece..81205c52735c 100644
> --- a/mm/page_cgroup.c
> +++ b/mm/page_cgroup.c
> @@ -130,7 +130,7 @@ struct page *lookup_cgroup_page(struct page_cgroup *pc)
>  	return page;
>  }
>  
> -static void *__init_refok alloc_page_cgroup(size_t size, int nid)
> +static void *__meminit alloc_page_cgroup(size_t size, int nid)
>  {
>  	void *addr = NULL;
>  
> @@ -162,7 +162,7 @@ static void free_page_cgroup(void *addr)
>  }
>  #endif
>  
> -static int __init_refok init_section_page_cgroup(unsigned long pfn)
> +static int __meminit init_section_page_cgroup(unsigned long pfn)
>  {
>  	struct page_cgroup *base, *pc;
>  	struct mem_section *section;
> -- 
> 1.7.4
> 
> --
> 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/ .
> Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>