[Devel] Re: [PATCH 04/11] kmem slab accounting basic infrastructure

[Glauber Costa]

On 06/26/2012 08:22 AM, David Rientjes wrote:
> On Mon, 25 Jun 2012, Glauber Costa wrote:
>
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index 9352d40..6f34b77 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -265,6 +265,10 @@ struct mem_cgroup {
>>   	};
>>
>>   	/*
>> +	 * the counter to account for kernel memory usage.
>> +	 */
>> +	struct res_counter kmem;
>> +	/*
>>   	 * Per cgroup active and inactive list, similar to the
>>   	 * per zone LRU lists.
>>   	 */
>> @@ -279,6 +283,7 @@ struct mem_cgroup {
>>   	 * Should the accounting and control be hierarchical, per subtree?
>>   	 */
>>   	bool use_hierarchy;
>> +	bool kmem_accounted;
>>
>>   	bool		oom_lock;
>>   	atomic_t	under_oom;
>> @@ -391,6 +396,7 @@ enum res_type {
>>   	_MEM,
>>   	_MEMSWAP,
>>   	_OOM_TYPE,
>> +	_KMEM,
>>   };
>>
>>   #define MEMFILE_PRIVATE(x, val)	((x) << 16 | (val))
>> @@ -1438,6 +1444,10 @@ done:
>>   		res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
>>   		res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
>>   		res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
>> +	printk(KERN_INFO "kmem: usage %llukB, limit %llukB, failcnt %llu\n",
>> +		res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
>> +		res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
>> +		res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
>>   }
>>
>>   /*
>> @@ -3879,6 +3889,11 @@ static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
>>   		else
>>   			val = res_counter_read_u64(&memcg->memsw, name);
>>   		break;
>> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
>> +	case _KMEM:
>> +		val = res_counter_read_u64(&memcg->kmem, name);
>> +		break;
>> +#endif
>
> This shouldn't need an #ifdef, ->kmem is available on all
> CONFIG_CGROUP_MEM_RES_CTLR kernels.  Same with several of the other
> instances in this patch.
>
> Can't these instances be addressed by not adding kmem_cgroup_files without
> CONFIG_CGROUP_MEM_RES_CTLR_KMEM?

Yes, it can.