On Thu, Mar 10, 2022 at 09:59:30AM +0100, Michal Hocko wrote: >On Wed 09-03-22 14:48:46, Michal Hocko wrote: >> [Cc Tim - the patch is http://lkml.kernel.org/r/20220308012047.26638-3-richard.weiyang@xxxxxxxxx] >> >> On Wed 09-03-22 00:46:20, Wei Yang wrote: >> > On Tue, Mar 08, 2022 at 09:17:58AM +0100, Michal Hocko wrote: >> > >On Tue 08-03-22 01:20:47, Wei Yang wrote: >> > >> next_mz is removed from rb_tree, let's add it back if no reclaim has >> > >> been tried. >> > > >> > >Could you elaborate more why we need/want this? >> > > >> > >> > Per my understanding, we add back the right most node even reclaim makes no >> > progress, so it is reasonable to add back a node if we didn't get a chance to >> > do reclaim on it. >> >> Your patch sounded familiar and I can remember now. The same fix has >> been posted by Tim last year >> https://lore.kernel.org/linux-mm/8d35206601ccf0e1fe021d24405b2a0c2f4e052f.1613584277.git.tim.c.chen@xxxxxxxxxxxxxxx/ > >Btw. I forgot to mention yesterday. Whatever was the reason this has >slipped through cracks it would great if you could reuse the changelog >of the original patch which was more verbose and explicit about the >underlying problem. The only remaining part I would add is a description >of how serious the problem is. The removed memcg would be out of the >excess tree until further memory charges would get it back. But that can >take arbitrary amount of time. Whether that is a real problem would >depend on the workload of course but considering how coarse of a tool >the soft limit is it is possible that this is not something most users >would even notice. Got it, would send a v2. >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me
