Messages in this thread | | | Date | Mon, 14 Sep 2015 18:35:59 +0530 | From | Raghavendra K T <> | Subject | 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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