On Wed, Sep 21, 2016 at 08:17:27PM +0530, Aneesh Kumar K.V wrote: > "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com> writes: > > > Joonsoo Kim <iamjoonsoo....@lge.com> writes: > > > >> On Tue, Aug 30, 2016 at 04:09:37PM +0530, Aneesh Kumar K.V wrote: > >>> Joonsoo Kim <js1...@gmail.com> writes: > >>> > >>> > 2016-08-29 18:27 GMT+09:00 Aneesh Kumar K.V > >>> > <aneesh.ku...@linux.vnet.ibm.com>: > >>> >> js1...@gmail.com writes: > >>> >> > >>> >>> From: Joonsoo Kim <iamjoonsoo....@lge.com> > >>> >>> > >>> >>> 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 ? > > > > Even though we have the issues of migration failures due to pinned and > THP pages in ZONE_CMA, overall the code is simpler. IMHO we should get > this upstream now and work on solving those issues later.
Yep! I will take a look on those problems after merging this patchset. > > You can add for the complete series. > > Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> Thanks!