On Thu, Sep 01, 2016 at 11:17:23AM +0530, Aneesh Kumar K.V wrote: > Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> writes: > > > On Tue, Aug 30, 2016 at 04:09:37PM +0530, Aneesh Kumar K.V wrote: > >> Joonsoo Kim <js1304@xxxxxxxxx> writes: > >> > >> > 2016-08-29 18:27 GMT+09:00 Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>: > >> >> js1304@xxxxxxxxx writes: > >> >> > >> >>> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > >> >>> > >> >>> Hello, > >> >>> > >> >>> Changes from v4 > >> >>> o Rebase on next-20160825 > >> >>> o Add general fix patch for lowmem reserve > >> >>> o Fix lowmem reserve ratio > >> >>> o Fix zone span optimizaion per Vlastimil > >> >>> o Fix pageset initialization > >> >>> o Change invocation timing on cma_init_reserved_areas() > >> >> > >> >> I don't see much information regarding how we interleave between > >> >> ZONE_CMA and other zones for movable allocation. Is that explained in > >> >> any of the patch ? The fair zone allocator got removed by > >> >> e6cbd7f2efb433d717af72aa8510a9db6f7a7e05 > >> > > >> > Interleaving would not work since the fair zone allocator policy is removed. > >> > I don't think that it's a big problem because it is just matter of > >> > timing to fill > >> > up the memory. Eventually, memory on ZONE_CMA will be fully used in > >> > any case. > >> > >> Does that mean a CMA allocation will now be slower because in most case we > >> will need to reclaim ? The zone list will now have ZONE_CMA in the > >> beginning right ? > > > > ZONE_CMA will be used first but I don't think that CMA allocation will > > be slower. In most case, memory would be fully used (usually > > by page cache). So, we need reclaim or migration in any case. > > Considering that the upstream kernel doesn't allow migration of THP > pages, this would mean that migrate will fail in most case if we have > THP enabled and the THP allocation request got satisfied via ZONE_CMA. > Isn't that going to be a problem ? I think that it is a separate problem. Once we restore utilization of CMA area, it would become a problem in any case. It is just hidden by utilization bug and should be handled separately. I guess that it's not that hard to fix that problem. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>