On 2022/8/10 00:45, Yang Shi wrote: > On Tue, Aug 9, 2022 at 2:08 AM Aaron Lu <aaron.lu@xxxxxxxxx> wrote: >> >> On Tue, Aug 09, 2022 at 09:12:57AM +0800, Yin Fengwei wrote: >>> Hi Yang, >>> >>> On 2022/8/9 01:49, Yang Shi wrote: >>>> The GFP_KERNEL is fine for most THP split callsites except for the >>>> memory reclaim path since it might not allow certain flags to avoid >>>> recursion, for example, nested reclaim, issue I/O, etc. The most >>>> filesystems clear __GFP_FS. However it should not be a real life >>>> problem now since AFAIK just xfs supports large folios for now and xfs >>>> uses iomap release_folio() method which actually ignores gfp flags. >>> Thanks a lot for the valuable comments. >>> >>> >>>> >>>> So it sounds safer to follow the gfp convention used by >>>> xas_split_alloc() in the below. The best way is to pass in the gfp >>>> flag from the reclaimer IMO, but it seems overkilling at the moment. >>> >>> It's possible that the gfp used by xas_split_alloc has __GFP_FS/IO set. >>> What about to use current_gfp_context(gfp_as_xas_split_alloc)? >>> >> >> Sounds reasonable to me. >> >> Also, the gfp used by xas_split_alloc() should also be modified to: >> current_gfp_context(mapping_gfp_mask(mapping) & GFP_RECLAIM_MASK)? >> Since they are in the same context. > > Good point, fine to me. Thanks both of your a lot for the comments. I will update the patch. Regards Yin, Fengwei
