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| author | Johannes Weiner <hannes@cmpxchg.org> | 2023-08-24 17:38:21 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-09-03 00:17:34 +0200 |
| commit | f945116e4e191cd543ecd56d9f13e6331494847c (patch) | |
| tree | 465a7a4b332a113aa5539f6abf58f6baca37aac2 /mm/page_alloc.c | |
| parent | MAINTAINERS: add rmap.h to mm entry (diff) | |
| download | linux-f945116e4e191cd543ecd56d9f13e6331494847c.tar.xz linux-f945116e4e191cd543ecd56d9f13e6331494847c.zip | |
mm: page_alloc: remove stale CMA guard code
In the past, movable allocations could be disallowed from CMA through
PF_MEMALLOC_PIN. As CMA pages are funneled through the MOVABLE pcplist,
this required filtering that cornercase during allocations, such that
pinnable allocations wouldn't accidentally get a CMA page.
However, since 8e3560d963d2 ("mm: honor PF_MEMALLOC_PIN for all movable
pages"), PF_MEMALLOC_PIN automatically excludes __GFP_MOVABLE. Once
again, MOVABLE implies CMA is allowed.
Remove the stale filtering code. Also remove a stale comment that was
introduced as part of the filtering code, because the filtering let
order-0 pages fall through to the buddy allocator. See 1d91df85f399
("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore}
APIs") for context. The comment's been obsolete since the introduction of
the explicit ALLOC_HIGHATOMIC flag in eb2e2b425c69 ("mm/page_alloc:
explicitly record high-order atomic allocations in alloc_flags").
Link: https://lkml.kernel.org/r/20230824153821.243148-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 452459836b71..0c5be12f9336 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2641,12 +2641,6 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone, do { page = NULL; spin_lock_irqsave(&zone->lock, flags); - /* - * order-0 request can reach here when the pcplist is skipped - * due to non-CMA allocation context. HIGHATOMIC area is - * reserved for high-order atomic allocation, so order-0 - * request should skip it. - */ if (alloc_flags & ALLOC_HIGHATOMIC) page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); if (!page) { @@ -2780,17 +2774,10 @@ struct page *rmqueue(struct zone *preferred_zone, WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); if (likely(pcp_allowed_order(order))) { - /* - * 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_pcplist(preferred_zone, zone, order, + migratetype, alloc_flags); + if (likely(page)) + goto out; } page = rmqueue_buddy(preferred_zone, zone, order, alloc_flags, |