On Thu, Apr 05, 2018 at 09:57:53AM +0200, Michal Hocko wrote: > On Thu 05-04-18 16:27:16, Joonsoo Kim wrote: > > From: Joonsoo Kim <iamjoonsoo....@lge.com> > > > > ZONE_MOVABLE only has movable pages so we don't need to keep enough > > freepages to avoid or deal with fragmentation. So, don't count it. > > > > This changes min_free_kbytes and thus min_watermark greatly > > if ZONE_MOVABLE is used. It will make the user uses more memory. > > OK, but why does it matter. Has anybody seen this as an issue?
There was a regression report for CMA patchset and I think that it is related to this problem. CMA patchset makes the system uses one more zone (ZONE_MOVABLE) and then increase min_free_kbytes. It reduces usable memory and it could cause regression. http://lkml.kernel.org/r/20180102063528.GG30397@yexl-desktop Thanks.