On 7/16/20 9:27 AM, Joonsoo Kim wrote: > 2020년 7월 15일 (수) 오후 5:24, Vlastimil Babka <vbabka@xxxxxxx>님이 작성: >> > /* >> > * get_page_from_freelist goes through the zonelist trying to allocate >> > * a page. >> > @@ -3706,6 +3714,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, >> > struct pglist_data *last_pgdat_dirty_limit = NULL; >> > bool no_fallback; >> > >> > + current_alloc_flags(gfp_mask, &alloc_flags); >> >> I don't see why to move the test here? It will still be executed in the >> fastpath, if that's what you wanted to avoid. > > I want to execute it on the fastpath, too. Reason that I moved it here > is that alloc_flags could be reset on slowpath. See the code where > __gfp_pfmemalloc_flags() is on. This is the only place that I can apply > this option to all the allocation paths at once. But get_page_from_freelist() might be called multiple times in the slowpath, and also anyone looking for gfp and alloc flags setup will likely not examine this function. I don't see a problem in having it in two places that already deal with alloc_flags setup, as it is now. > Thanks. > >> > + >> > retry: >> > /* >> > * Scan zonelist, looking for a zone with enough free. >> > @@ -4339,10 +4349,6 @@ gfp_to_alloc_flags(gfp_t gfp_mask) >> > } else if (unlikely(rt_task(current)) && !in_interrupt()) >> > alloc_flags |= ALLOC_HARDER; >> > >> > -#ifdef CONFIG_CMA >> > - if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) >> > - alloc_flags |= ALLOC_CMA; >> > -#endif >> >> I would just replace this here with: >> alloc_flags = current_alloc_flags(gfp_mask, alloc_flags); >> >> > return alloc_flags; >> > } >> > >> > @@ -4808,9 +4814,6 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, >> > if (should_fail_alloc_page(gfp_mask, order)) >> > return false; >> > >> > - if (IS_ENABLED(CONFIG_CMA) && ac->migratetype == MIGRATE_MOVABLE) >> > - *alloc_flags |= ALLOC_CMA; >> >> And same here... Ah, I see. current_alloc_flags() should probably take a >> migratetype parameter instead of gfp_mask then. >> >> > - >> > return true; >> > } >> > >> > >> >
