Messages in this thread | ![/](/images/icornerl.gif) | | From | Jianyu Zhan <> | Date | Tue, 22 Apr 2014 18:58:11 +0800 | Subject | Re: [PATCH 1/2] mm/memcontrol.c: remove meaningless while loop in mem_cgroup_iter() |
| |
On Tue, Apr 22, 2014 at 6:34 PM, Michal Hocko <mhocko@suse.cz> wrote: > 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?
Hi, Michal,
Good catch, it makes sense ! This reminds me of my draft edition of this patch, I specifically handle this case as:
if (reclaim) { if (!memcg ) { iter->generation++; if (!prev) { memcg = root; mem_cgroup_iter_update(iter, NULL, memcg, root, seq); goto out_unlock: } } mem_cgroup_iter_update(iter, last_visited, memcg, root, seq); if (!prev && memcg) reclaim->generation = iter->generation; }
This is literally manual unwinding the second while loop, and thus omit the while loop, to save a mem_cgroup_iter_update() and a mem_cgroup_iter_update()
But it maybe a bit hard to read.
If it is OK, I could resend a new one.
Thanks, Jianyu Zhan
| ![\](/images/icornerr.gif) |