Re: [PATCH next-20130703] net: sock: Add ifdef CONFIG_MEMCG_KMEM for mem_cgroup_sockets_{init,destroy}

Sedat Dilek
2013-07-03T15:53:25Z

On Wed, Jul 3, 2013 at 5:20 PM, Michal Hocko <mhocko@suse.cz> wrote:
> On Wed 03-07-13 20:51:00, Li Zefan wrote:
> [...]
>> [PATCH] memcg: fix build error if CONFIG_MEMCG_KMEM=n
>>
>> Fix this build error:
>>
>> mm/built-in.o: In function `mem_cgroup_css_free':
>> memcontrol.c:(.text+0x5caa6): undefined reference to
>> 'mem_cgroup_sockets_destroy'
>>
>> Reported-by: Fengguang Wu <fengguang.wu@intel.com>
>> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
>> Signed-off-by: Li Zefan <lizefan@huawei.com>
>
> I am seeing the same thing I just didn't get to reporting it.
> The other approach is not bad as well but I find this tiny better
> because mem_cgroup_css_free should care only about a single cleanup
> function for whole kmem. If that one needs to do tcp kmem specific
> cleanup then it should be done inside kmem_cgroup_css_offline.
>

As said in my other mail, for me this makes sense as it is a followup.

But, still I don't know why sock.c has is own mem_cgroup_sockets_{init,destroy}.
It's interesting, that include/net/sock.h is included by sock.c, too.
If they are different, why do both function use the same name?

> Andrew could you add this as
> memcg-use-css_get-put-when-charging-uncharging-kmem-fix.patch, please?
>

*-fix-2 as there is *-fix already around.

- Sedat -

http://ozlabs.org/~akpm/mmotm/broken-out/memcg-use-css_get-put-when-charging-uncharging-kmem-fix.patch

> Acked-by: Michal Hocko <mhocko@suse.cz>
>
> Thanks
>
>> ---
>> mm/memcontrol.c | 12 ++++++++++--
>> 1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index 234f311..59ea6f9 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -5876,6 +5876,11 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
>> return mem_cgroup_sockets_init(memcg, ss);
>> }
>>
>> +static void memcg_destroy_kmem(struct mem_cgroup *memcg)
>> +{
>> + mem_cgroup_sockets_destroy(memcg);
>> +}
>> +
>> static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
>> {
>> if (!memcg_kmem_is_active(memcg))
>> @@ -5915,6 +5920,10 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
>> return 0;
>> }
>>
>> +static void memcg_destroy_kmem(struct mem_cgroup *memcg)
>> +{
>> +}
>> +
>> static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
>> {
>> }
>> @@ -6312,8 +6321,7 @@ static void mem_cgroup_css_free(struct cgroup *cont)
>> {
>> struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
>>
>> - mem_cgroup_sockets_destroy(memcg);
>> -
>> + memcg_destroy_kmem(memcg);
>> __mem_cgroup_free(memcg);
>> }
>>
>> --
>> 1.8.0.2
>>
>>
>> > ---
>> > [ v2: git dislikes lines beginning with hash ('#'). ]
>> >
>> > include/net/sock.h | 4 +++-
>> > 1 file changed, 3 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/include/net/sock.h b/include/net/sock.h
>> > index ea6206c..ad4bf7f 100644
>> > --- a/include/net/sock.h
>> > +++ b/include/net/sock.h
>> > @@ -71,6 +71,7 @@
>> > struct cgroup;
>> > struct cgroup_subsys;
>> > #ifdef CONFIG_NET
>> > +#ifdef CONFIG_MEMCG_KMEM
>>
>> #if defined(CONFIG_NET) && defined(CONFIG_MEMCG_KMEM)
>>
>> > int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
>> > void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
>> > #else
>> > @@ -83,7 +84,8 @@ static inline
>> > void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
>> > {
>> > }
>> > -#endif
>> > +#endif /* CONFIG_NET */
>> > +#endif /* CONFIG_MEMCG_KMEM */
>> > /*
>> > * This structure really needs to be cleaned up.
>> > * Most of it is for TCP, and not used by any of
>> >
>>
>> --
>> 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: email@kvack.org
>
> --
> Michal Hocko
> SUSE Labs