linux-kernel - Re: [PATCH RFC] mm/memcg: calculate max hierarchy limit number instead of min

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120712093211.GC3181@kernel>
Date:	Thu, 12 Jul 2012 17:32:11 +0800
From:	Wanpeng Li <liwp.linux@...il.com>
To:	Michal Hocko <mhocko@...e.cz>
Cc:	linux-mm@...ck.org, Johannes Weiner <hannes@...xchg.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	cgroups@...r.kernel.org, linux-kernel@...r.kernel.org,
	Wanpeng Li <liwp.linux@...il.com>
Subject: Re: [PATCH RFC] mm/memcg: calculate max hierarchy limit number
 instead of min

On Wed, Jul 11, 2012 at 03:47:57PM +0200, Michal Hocko wrote:
>On Wed 11-07-12 21:24:41, Wanpeng Li wrote:
>> From: Wanpeng Li <liwp@...ux.vnet.ibm.com>
>> 
>> Since hierachical_memory_limit shows "of bytes of memory limit with
>> regard to hierarchy under which the memory cgroup is", the count should
>> calculate max hierarchy limit when use_hierarchy in order to show hierarchy
>> subtree limit. hierachical_memsw_limit is the same case.
>
>No the patch is wrong. The hierarchical limit says when we start
>reclaiming in the hierarchy and that one is triggered on smallest limit
>up the way to the hierarchy root.

I see function mem_cgroup_hierachy_reclaim is removal, and hierarchical
reclaim is still work? Could you explain me how it works in details, 
thank you for your time Michal.

Thanks & Best Regards,
Wanpeng Li
>
>What are you trying to accomplish here?
>
>> Signed-off-by: Wanpeng Li <liwp.linux@...il.com>
>> ---
>>  mm/memcontrol.c |   14 +++++++-------
>>  1 files changed, 7 insertions(+), 7 deletions(-)
>> 
>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
>> index 69a7d45..6392c0a 100644
>> --- a/mm/memcontrol.c
>> +++ b/mm/memcontrol.c
>> @@ -3929,10 +3929,10 @@ static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
>>  		unsigned long long *mem_limit, unsigned long long *memsw_limit)
>>  {
>>  	struct cgroup *cgroup;
>> -	unsigned long long min_limit, min_memsw_limit, tmp;
>> +	unsigned long long max_limit, max_memsw_limit, tmp;
>>  
>> -	min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
>> -	min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
>> +	max_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
>> +	max_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
>>  	cgroup = memcg->css.cgroup;
>>  	if (!memcg->use_hierarchy)
>>  		goto out;
>> @@ -3943,13 +3943,13 @@ static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
>>  		if (!memcg->use_hierarchy)
>>  			break;
>>  		tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
>> -		min_limit = min(min_limit, tmp);
>> +		max_limit = max(max_limit, tmp);
>>  		tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
>> -		min_memsw_limit = min(min_memsw_limit, tmp);
>> +		max_memsw_limit = max(max_memsw_limit, tmp);
>>  	}
>>  out:
>> -	*mem_limit = min_limit;
>> -	*memsw_limit = min_memsw_limit;
>> +	*mem_limit = max_limit;
>> +	*memsw_limit = max_memsw_limit;
>>  }
>>  
>>  static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
>> -- 
>> 1.7.5.4
>> 
>
>-- 
>Michal Hocko
>SUSE Labs
>SUSE LINUX s.r.o.
>Lihovarska 1060/12
>190 00 Praha 9    
>Czech Republic
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/