lkml.org 
[lkml]   [2013]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] memcg: stop warning on memcg_propagate_kmem
On 02/04/2013 11:57 AM, Michal Hocko wrote:
> On Sun 03-02-13 20:29:01, Hugh Dickins wrote:
>> Whilst I run the risk of a flogging for disloyalty to the Lord of Sealand,
>> I do have CONFIG_MEMCG=y CONFIG_MEMCG_KMEM not set, and grow tired of the
>> "mm/memcontrol.c:4972:12: warning: `memcg_propagate_kmem' defined but not
>> used [-Wunused-function]" seen in 3.8-rc: move the #ifdef outwards.
>>
>> Signed-off-by: Hugh Dickins <hughd@google.com>
>
> Acked-by: Michal Hocko <mhocko@suse.cz>
>
> Hmm, if you are not too tired then moving the function downwards to
> where it is called (memcg_init_kmem) will reduce the number of ifdefs.
> But this can wait for a bigger clean up which is getting due:
> git grep "def.*CONFIG_MEMCG_KMEM" mm/memcontrol.c | wc -l
> 12
>

The problem is that I was usually keeping things in clearly separated
blocks, like this :

#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
struct tcp_memcontrol tcp_mem;
#endif
#if defined(CONFIG_MEMCG_KMEM)
/* analogous to slab_common's slab_caches list. per-memcg */
struct list_head memcg_slab_caches;
/* Not a spinlock, we can take a lot of time walking the list */
struct mutex slab_caches_mutex;
/* Index in the kmem_cache->memcg_params->memcg_caches array */
int kmemcg_id;
#endif

If it would be preferable to everybody, this could be easily rewritten as:

#if defined(CONFIG_MEMCG_KMEM)
#if defined(CONFIG_INET)
struct tcp_memcontrol tcp_mem;
#endif
/* analogous to slab_common's slab_caches list. per-memcg */
struct list_head memcg_slab_caches;
/* Not a spinlock, we can take a lot of time walking the list */
struct mutex slab_caches_mutex;
/* Index in the kmem_cache->memcg_params->memcg_caches array */
int kmemcg_id;
#endif

This would allow us to collapse some blocks a bit down as well.

It doesn't bother me *that* much, though.

> Thanks
>> ---
>>
>> mm/memcontrol.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> --- 3.8-rc6/mm/memcontrol.c 2012-12-22 09:43:27.628015582 -0800
>> +++ linux/mm/memcontrol.c 2013-02-02 16:56:06.188325771 -0800
>> @@ -4969,6 +4969,7 @@ out:
>> return ret;
>> }
>>
>> +#ifdef CONFIG_MEMCG_KMEM
>> static int memcg_propagate_kmem(struct mem_cgroup *memcg)
>> {
>> int ret = 0;
>> @@ -4977,7 +4978,6 @@ static int memcg_propagate_kmem(struct m
>> goto out;
>>
>> memcg->kmem_account_flags = parent->kmem_account_flags;
>> -#ifdef CONFIG_MEMCG_KMEM
>> /*
>> * When that happen, we need to disable the static branch only on those
>> * memcgs that enabled it. To achieve this, we would be forced to
>> @@ -5003,10 +5003,10 @@ static int memcg_propagate_kmem(struct m
>> mutex_lock(&set_limit_mutex);
>> ret = memcg_update_cache_sizes(memcg);
>> mutex_unlock(&set_limit_mutex);
>> -#endif
>> out:
>> return ret;
>> }
>> +#endif /* CONFIG_MEMCG_KMEM */
>>
>> /*
>> * The user of this function is...
>



\
 
 \ /
  Last update: 2013-02-04 10:03    [W:0.046 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site