2020년 7월 8일 (수) 오후 4:48, Michal Hocko <mhocko@xxxxxxxxxx>님이 작성: > > On Wed 08-07-20 16:19:17, Joonsoo Kim wrote: > > On Tue, Jul 07, 2020 at 01:40:19PM +0200, Michal Hocko wrote: > [...] > > Subject: [PATCH] mm/migrate: clear __GFP_RECLAIM for THP allocation for > > migration > > > > In migration target allocation functions, THP allocations uses different > > gfp_mask, especially, in regard to the reclaim gfp_mask. There is no > > reason to use different reclaim gfp_mask for each cases and it is > > an obstacle to make a common function in order to clean-up migration > > target allocation functions. This patch fixes this situation by using > > common reclaim gfp_mask for THP allocation. > > I would find the following more understandable, feel free to reuse parts > that you like: > " > new_page_nodemask is a migration callback and it tries to use a common > gfp flags for the target page allocation whether it is a base page or a > THP. The later only adds GFP_TRANSHUGE to the given mask. This results > in the allocation being slightly more aggressive than necessary because > the resulting gfp mask will contain also __GFP_RECLAIM_KSWAPD. THP > allocations usually exclude this flag to reduce over eager background > reclaim during a high THP allocation load which has been seen during > large mmaps initialization. There is no indication that this is a > problem for migration as well but theoretically the same might happen > when migrating large mappings to a different node. Make the migration > callback consistent with regular THP allocations. > " Looks good! I will use this description. Thanks.
