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Re: [PATCH 1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru

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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;
}


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[PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node in list lru Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> - 2015-09-08 20:40 +0200
  Re: [PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node  in list lru Vladimir Davydov <vdavydov@parallels.com> - 2015-09-14 11:10 +0200
    Re: [PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node  in list lru Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> - 2015-09-14 13:40 +0200
      Re: [PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node  in list lru Vladimir Davydov <vdavydov@parallels.com> - 2015-09-14 14:10 +0200
        Re: [PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node  in list lru Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> - 2015-09-14 15:10 +0200
          Re: [PATCH  1/2] mm: Replace nr_node_ids for loop with for_each_node  in list lru Vladimir Davydov <vdavydov@parallels.com> - 2015-09-14 15:30 +0200

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