lkml.org 
[lkml]   [2015]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru
On 09/14/2015 05:34 PM, Vladimir Davydov wrote:
> On Mon, Sep 14, 2015 at 05:09:31PM +0530, Raghavendra K T wrote:
>> On 09/14/2015 02:30 PM, Vladimir Davydov wrote:
>>> On Wed, Sep 09, 2015 at 12:01:46AM +0530, Raghavendra K T wrote:
>>>> The functions used in the patch are in slowpath, which gets called
>>>> whenever alloc_super is called during mounts.
>>>>
>>>> Though this should not make difference for the architectures with
>>>> sequential numa node ids, for the powerpc which can potentially have
>>>> sparse node ids (for e.g., 4 node system having numa ids, 0,1,16,17
>>>> is common), this patch saves some unnecessary allocations for
>>>> non existing numa nodes.
>>>>
>>>> Even without that saving, perhaps patch makes code more readable.
>>>
>>> Do I understand correctly that node 0 must always be in
>>> node_possible_map? I ask, because we currently test
>>> lru->node[0].memcg_lrus to determine if the list is memcg aware.
>>>
>>
>> Yes, node 0 is always there. So it should not be a problem.
>
> I think it should be mentioned in the comment to list_lru_memcg_aware
> then.
>

Something like this: ?
static inline bool list_lru_memcg_aware(struct list_lru *lru)
{
/*
* This needs node 0 to be always present, even
* in the systems supporting sparse numa ids.
*/
return !!lru->node[0].memcg_lrus;
}




\
 
 \ /
  Last update: 2015-09-14 15:21    [W:0.105 / U:1.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site