2018-04-21 13:37:14

by wanglong

Subject: [PATCH] memcg: writeback: use memcg->cgwb_list directly

Signed-off-by: Wang Long <[email protected]>
---
include/linux/memcontrol.h | 1 -
mm/backing-dev.c | 4 ++--
mm/memcontrol.c | 5 -----
3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d99b71b..c0056e0 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1093,7 +1093,6 @@ static inline void dec_lruvec_page_state(struct page *page,

#ifdef CONFIG_CGROUP_WRITEBACK

-struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
unsigned long *pheadroom, unsigned long *pdirty,
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 023190c..0a48e05 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -555,7 +555,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
memcg = mem_cgroup_from_css(memcg_css);
blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
blkcg = css_to_blkcg(blkcg_css);
- memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
+ memcg_cgwb_list = &memcg->cgwb_list;
blkcg_cgwb_list = &blkcg->cgwb_list;

/* look up again under lock and discard on blkcg mismatch */
@@ -734,7 +734,7 @@ static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
*/
void wb_memcg_offline(struct mem_cgroup *memcg)
{
- struct list_head *memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
+ struct list_head *memcg_cgwb_list = &memcg->cgwb_list;
struct bdi_writeback *wb, *next;

spin_lock_irq(&cgwb_lock);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e074f7c..d1adb9c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3562,11 +3562,6 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,

#ifdef CONFIG_CGROUP_WRITEBACK

-struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
-{
- return &memcg->cgwb_list;
-}
-
static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
{
return wb_domain_init(&memcg->cgwb_domain, gfp);
--
1.8.3.1

2018-04-21 23:55:02

by Jan Kara

Subject: Re: [PATCH] memcg: writeback: use memcg->cgwb_list directly

On Sat 21-04-18 21:29:41, Wang Long wrote:
> Signed-off-by: Wang Long <[email protected]>

Yeah, looks good. I guess it was originally intended to avoid compilation
errors if CONFIG_CGROUP_WRITEBACK was disabled. But it doesn't seem likely
we'll ever need that list outside of code under CONFIG_CGROUP_WRITEBACK. So
you can add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> include/linux/memcontrol.h | 1 -
> mm/backing-dev.c | 4 ++--
> mm/memcontrol.c | 5 -----
> 3 files changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index d99b71b..c0056e0 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1093,7 +1093,6 @@ static inline void dec_lruvec_page_state(struct page *page,
>
> #ifdef CONFIG_CGROUP_WRITEBACK
>
> -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
> struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
> void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
> unsigned long *pheadroom, unsigned long *pdirty,
> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 023190c..0a48e05 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -555,7 +555,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
> memcg = mem_cgroup_from_css(memcg_css);
> blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
> blkcg = css_to_blkcg(blkcg_css);
> - memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
> + memcg_cgwb_list = &memcg->cgwb_list;
> blkcg_cgwb_list = &blkcg->cgwb_list;
>
> /* look up again under lock and discard on blkcg mismatch */
> @@ -734,7 +734,7 @@ static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
> */
> void wb_memcg_offline(struct mem_cgroup *memcg)
> {
> - struct list_head *memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
> + struct list_head *memcg_cgwb_list = &memcg->cgwb_list;
> struct bdi_writeback *wb, *next;
>
> spin_lock_irq(&cgwb_lock);
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index e074f7c..d1adb9c 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3562,11 +3562,6 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
>
> #ifdef CONFIG_CGROUP_WRITEBACK
>
> -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
> -{
> - return &memcg->cgwb_list;
> -}
> -
> static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
> {
> return wb_domain_init(&memcg->cgwb_domain, gfp);
> --
> 1.8.3.1
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2018-04-22 12:44:51

by Michal Hocko

Subject: Re: [PATCH] memcg: writeback: use memcg->cgwb_list directly

On Sun 22-04-18 01:50:57, Jan Kara wrote:
> On Sat 21-04-18 21:29:41, Wang Long wrote:
> > Signed-off-by: Wang Long <[email protected]>
>
> Yeah, looks good. I guess it was originally intended to avoid compilation
> errors if CONFIG_CGROUP_WRITEBACK was disabled. But it doesn't seem likely
> we'll ever need that list outside of code under CONFIG_CGROUP_WRITEBACK. So
> you can add:

Yeah. Trivial wrappers like these are usualy more harm than goot. But
please add _some_ words in the changelog.

> Reviewed-by: Jan Kara <[email protected]>
>
> Honza
>
> > ---
> > include/linux/memcontrol.h | 1 -
> > mm/backing-dev.c | 4 ++--
> > mm/memcontrol.c | 5 -----
> > 3 files changed, 2 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> > index d99b71b..c0056e0 100644
> > --- a/include/linux/memcontrol.h
> > +++ b/include/linux/memcontrol.h
> > @@ -1093,7 +1093,6 @@ static inline void dec_lruvec_page_state(struct page *page,
> >
> > #ifdef CONFIG_CGROUP_WRITEBACK
> >
> > -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
> > struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
> > void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
> > unsigned long *pheadroom, unsigned long *pdirty,
> > diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> > index 023190c..0a48e05 100644
> > --- a/mm/backing-dev.c
> > +++ b/mm/backing-dev.c
> > @@ -555,7 +555,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
> > memcg = mem_cgroup_from_css(memcg_css);
> > blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
> > blkcg = css_to_blkcg(blkcg_css);
> > - memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
> > + memcg_cgwb_list = &memcg->cgwb_list;
> > blkcg_cgwb_list = &blkcg->cgwb_list;
> >
> > /* look up again under lock and discard on blkcg mismatch */
> > @@ -734,7 +734,7 @@ static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
> > */
> > void wb_memcg_offline(struct mem_cgroup *memcg)
> > {
> > - struct list_head *memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
> > + struct list_head *memcg_cgwb_list = &memcg->cgwb_list;
> > struct bdi_writeback *wb, *next;
> >
> > spin_lock_irq(&cgwb_lock);
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > index e074f7c..d1adb9c 100644
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -3562,11 +3562,6 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
> >
> > #ifdef CONFIG_CGROUP_WRITEBACK
> >
> > -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
> > -{
> > - return &memcg->cgwb_list;
> > -}
> > -
> > static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
> > {
> > return wb_domain_init(&memcg->cgwb_domain, gfp);
> > --
> > 1.8.3.1
> >
> --
> Jan Kara <[email protected]>
> SUSE Labs, CR

--
Michal Hocko
SUSE Labs

2018-04-22 15:07:31

by wanglong

Subject: Re: [PATCH] memcg: writeback: use memcg->cgwb_list directly

On 22/4/2018 8:43 PM, Michal Hocko wrote:
> On Sun 22-04-18 01:50:57, Jan Kara wrote:
>> On Sat 21-04-18 21:29:41, Wang Long wrote:
>>> Signed-off-by: Wang Long <[email protected]>
>> Yeah, looks good. I guess it was originally intended to avoid compilation
>> errors if CONFIG_CGROUP_WRITEBACK was disabled. But it doesn't seem likely
>> we'll ever need that list outside of code under CONFIG_CGROUP_WRITEBACK. So
>> you can add:
> Yeah. Trivial wrappers like these are usualy more harm than goot. But
> please add _some_ words in the changelog.
ok, I will send the v2 patch.
>> Reviewed-by: Jan Kara <[email protected]>
>>
>> Honza
>>
>>> ---
>>> include/linux/memcontrol.h | 1 -
>>> mm/backing-dev.c | 4 ++--
>>> mm/memcontrol.c | 5 -----
>>> 3 files changed, 2 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
>>> index d99b71b..c0056e0 100644
>>> --- a/include/linux/memcontrol.h
>>> +++ b/include/linux/memcontrol.h
>>> @@ -1093,7 +1093,6 @@ static inline void dec_lruvec_page_state(struct page *page,
>>>
>>> #ifdef CONFIG_CGROUP_WRITEBACK
>>>
>>> -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg);
>>> struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb);
>>> void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
>>> unsigned long *pheadroom, unsigned long *pdirty,
>>> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
>>> index 023190c..0a48e05 100644
>>> --- a/mm/backing-dev.c
>>> +++ b/mm/backing-dev.c
>>> @@ -555,7 +555,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
>>> memcg = mem_cgroup_from_css(memcg_css);
>>> blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
>>> blkcg = css_to_blkcg(blkcg_css);
>>> - memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
>>> + memcg_cgwb_list = &memcg->cgwb_list;
>>> blkcg_cgwb_list = &blkcg->cgwb_list;
>>>
>>> /* look up again under lock and discard on blkcg mismatch */
>>> @@ -734,7 +734,7 @@ static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
>>> */
>>> void wb_memcg_offline(struct mem_cgroup *memcg)
>>> {
>>> - struct list_head *memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
>>> + struct list_head *memcg_cgwb_list = &memcg->cgwb_list;
>>> struct bdi_writeback *wb, *next;
>>>
>>> spin_lock_irq(&cgwb_lock);
>>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>>> index e074f7c..d1adb9c 100644
>>> --- a/mm/memcontrol.c
>>> +++ b/mm/memcontrol.c
>>> @@ -3562,11 +3562,6 @@ static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
>>>
>>> #ifdef CONFIG_CGROUP_WRITEBACK
>>>
>>> -struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg)
>>> -{
>>> - return &memcg->cgwb_list;
>>> -}
>>> -
>>> static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
>>> {
>>> return wb_domain_init(&memcg->cgwb_domain, gfp);
>>> --
>>> 1.8.3.1
>>>
>> --
>> Jan Kara <[email protected]>
>> SUSE Labs, CR