Messages in this thread | ![/](/images/icornerl.gif) | | From | Jianyu Zhan <> | Date | Tue, 22 Apr 2014 18:17:09 +0800 | Subject | Re: [PATCH 1/2] mm/memcontrol.c: remove meaningless while loop in mem_cgroup_iter() |
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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.
This is what comments above mem_cgroup_iter() says:
>Returns references to children of the hierarchy below @root, or >* @root itself, or %NULL after a full round-trip.
Actually, this condition could be reduced to conditon 2.1
Thanks, Jianyu Zhan
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