Re: [PATCH RFC v3 04/35] mm: page_alloc: Partially revert "mm: page_alloc: remove stale CMA guard code"
From: Anshuman Khandual <hidden>
Date: 2024-01-29 09:01:37
Also in:
kvmarm, linux-arch, linux-arm-kernel, linux-fsdevel, linux-mm, lkml
On 1/25/24 22:12, Alexandru Elisei wrote:
The patch f945116e4e19 ("mm: page_alloc: remove stale CMA guard code")
removed the CMA filter when allocating from the MIGRATE_MOVABLE pcp list
because CMA is always allowed when __GFP_MOVABLE is set.
With the introduction of the arch_alloc_cma() function, the above is not
true anymore, so bring back the filter.This makes sense as arch_alloc_cma() now might prevent ALLOC_CMA being assigned to alloc_flags in gfp_to_alloc_flags_cma().
quoted hunk ↗ jump to hunk
This is a partially revert because the stale comment remains removed. Signed-off-by: Alexandru Elisei <redacted> --- mm/page_alloc.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a96d47a6393e..0fa34bcfb1af 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c@@ -2897,10 +2897,17 @@ struct page *rmqueue(struct zone *preferred_zone, WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); if (likely(pcp_allowed_order(order))) { - page = rmqueue_pcplist(preferred_zone, zone, order, - migratetype, alloc_flags); - if (likely(page)) - goto out; + /* + * MIGRATE_MOVABLE pcplist could have the pages on CMA area and + * we need to skip it when CMA area isn't allowed. + */ + if (!IS_ENABLED(CONFIG_CMA) || alloc_flags & ALLOC_CMA || + migratetype != MIGRATE_MOVABLE) { + page = rmqueue_pcplist(preferred_zone, zone, order, + migratetype, alloc_flags); + if (likely(page)) + goto out; + } } page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags,