Messages in this thread | | | Date | Tue, 22 Apr 2014 12:34:21 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 1/2] mm/memcontrol.c: remove meaningless while loop in mem_cgroup_iter() |
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On Tue 22-04-14 18:17:09, Jianyu Zhan wrote: > On Tue, Apr 22, 2014 at 5:47 PM, Michal Hocko <mhocko@suse.cz> wrote: > > What about > > 3. last_visited == last_node in the tree > > > > __mem_cgroup_iter_next returns NULL and the iterator would return > > without visiting anything. > > Hi, Michal, > > yep, if 3 last_visited == last_node, then this means we have done a round-trip, > thus __mem_cgroup_iter_next returns NULL, in turn mem_cgroup_iter() return NULL.
Sorry, I should have been more specific that I was talking about mem_cgroup_reclaim_cookie path where the iteration for this particular zone and priority ended at the last node without finishing the full roundtrip last time. This new iteration (prev==NULL) wants to continue and it should start a new roundtrip.
Makes sense? -- Michal Hocko SUSE Labs
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