On Thu, Mar 10, 2022 at 09:53:59AM +0100, Michal Hocko wrote: >On Thu 10-03-22 01:13:50, Wei Yang wrote: >> On Wed, Mar 09, 2022 at 02:48:45PM +0100, 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/ >> >It was posted with other changes to the soft limit code which I didn't >> >like but I have acked this particular one. Not sure what has happened >> >with it afterwards. >> >> Because of this ? >> 4f09feb8bf: vm-scalability.throughput -4.3% regression >> https://lore.kernel.org/linux-mm/20210302062521.GB23892@xsang-OptiPlex-9020/ > >That was a regression for a different patch in the series AFAICS: >: FYI, we noticed a -4.3% regression of vm-scalability.throughput due to commit: >: >: commit: 4f09feb8bf083be3834080ddf3782aee12a7c3f7 ("mm: Force update of mem cgroup soft limit tree on usage excess") > >That patch has played with how often memcg_check_events is called and >that can lead to a visible performance difference. Yes, I mean maybe because of this regression, the whole patch set is removed. >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me
