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| author | Mel Gorman <mgorman@techsingularity.net> | 2023-01-13 11:12:14 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-08 16:25:55 +0100 |
| commit | 17dedfd6de69a2263a2a5b414ad57eaf5176e060 (patch) | |
| tree | b51e64fbd6044c7add3d80bbfa8208ea69839307 /mm/page_alloc.c | |
| parent | 9da195a2d35b7631c59b80fcc58aeec67e3d1385 (diff) | |
| download | linux-17dedfd6de69a2263a2a5b414ad57eaf5176e060.tar.gz linux-17dedfd6de69a2263a2a5b414ad57eaf5176e060.tar.bz2 linux-17dedfd6de69a2263a2a5b414ad57eaf5176e060.zip | |
mm/page_alloc: explicitly record high-order atomic allocations in alloc_flags
[ Upstream commit eb2e2b425c6984ca8034448a3f2c680622bd3d4d ]
A high-order ALLOC_HARDER allocation is assumed to be atomic. While that
is accurate, it changes later in the series. In preparation, explicitly
record high-order atomic allocations in gfp_to_alloc_flags().
Link: https://lkml.kernel.org/r/20230113111217.14134-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 281dd25c1a01 ("mm/page_alloc: let GFP_ATOMIC order-0 allocs access highatomic reserves")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 72835cf4034b..43122de999c4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3614,10 +3614,20 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone, * reserved for high-order atomic allocation, so order-0 * request should skip it. */ - if (order > 0 && alloc_flags & ALLOC_HARDER) + if (alloc_flags & ALLOC_HIGHATOMIC) page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); if (!page) { page = __rmqueue(zone, order, migratetype, alloc_flags); + + /* + * If the allocation fails, allow OOM handling access + * to HIGHATOMIC reserves as failing now is worse than + * failing a high-order atomic allocation in the + * future. + */ + if (!page && (alloc_flags & ALLOC_OOM)) + page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); + if (!page) { spin_unlock_irqrestore(&zone->lock, flags); return NULL; @@ -3912,8 +3922,10 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, return true; } #endif - if (alloc_harder && !free_area_empty(area, MIGRATE_HIGHATOMIC)) + if ((alloc_flags & (ALLOC_HIGHATOMIC|ALLOC_OOM)) && + !free_area_empty(area, MIGRATE_HIGHATOMIC)) { return true; + } } return false; } @@ -4172,7 +4184,7 @@ try_this_zone: * If this is a high-order atomic allocation then check * if the pageblock should be reserved for the future */ - if (unlikely(order && (alloc_flags & ALLOC_HARDER))) + if (unlikely(alloc_flags & ALLOC_HIGHATOMIC)) reserve_highatomic_pageblock(page, zone, order); return page; @@ -4691,7 +4703,7 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask, } static inline unsigned int -gfp_to_alloc_flags(gfp_t gfp_mask) +gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order) { unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; @@ -4717,8 +4729,13 @@ gfp_to_alloc_flags(gfp_t gfp_mask) * Not worth trying to allocate harder for __GFP_NOMEMALLOC even * if it can't schedule. */ - if (!(gfp_mask & __GFP_NOMEMALLOC)) + if (!(gfp_mask & __GFP_NOMEMALLOC)) { alloc_flags |= ALLOC_HARDER; + + if (order > 0) + alloc_flags |= ALLOC_HIGHATOMIC; + } + /* * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the * comment for __cpuset_node_allowed(). @@ -4946,7 +4963,7 @@ restart: * kswapd needs to be woken up, and to avoid the cost of setting up * alloc_flags precisely. So we do that now. */ - alloc_flags = gfp_to_alloc_flags(gfp_mask); + alloc_flags = gfp_to_alloc_flags(gfp_mask, order); /* * We need to recalculate the starting point for the zonelist iterator |