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author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2020-08-06 23:26:04 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 11:33:29 -0700 |
commit | 8510e69c8efef82f2b37ea3e8ea19a27122c533e (patch) | |
tree | 41e4a0fc437e4e723bece37ca7ebc8005c26c68f /mm | |
parent | 182f3d7a02fddd9e4b1181c2ba710a930e05ddbb (diff) | |
download | linux-8510e69c8efef82f2b37ea3e8ea19a27122c533e.tar.bz2 |
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
Currently, memalloc_nocma_{save/restore} API that prevents CMA area
in page allocation is implemented by using current_gfp_context(). However,
there are two problems of this implementation.
First, this doesn't work for allocation fastpath. In the fastpath,
original gfp_mask is used since current_gfp_context() is introduced in
order to control reclaim and it is on slowpath. So, CMA area can be
allocated through the allocation fastpath even if
memalloc_nocma_{save/restore} APIs are used. Currently, there is just
one user for these APIs and it has a fallback method to prevent actual
problem.
Second, clearing __GFP_MOVABLE in current_gfp_context() has a side effect
to exclude the memory on the ZONE_MOVABLE for allocation target.
To fix these problems, this patch changes the implementation to exclude
CMA area in page allocation. Main point of this change is using the
alloc_flags. alloc_flags is mainly used to control allocation so it fits
for excluding CMA area in allocation.
Fixes: d7fefcc8de91 (mm/cma: add PF flag to force non cma alloc)
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Link: http://lkml.kernel.org/r/1595468942-29687-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/page_alloc.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9f9e15a502ae..167732f4d124 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2785,7 +2785,7 @@ __rmqueue(struct zone *zone, unsigned int order, int migratetype, * allocating from CMA when over half of the zone's free memory * is in the CMA area. */ - if (migratetype == MIGRATE_MOVABLE && + if (alloc_flags & ALLOC_CMA && zone_page_state(zone, NR_FREE_CMA_PAGES) > zone_page_state(zone, NR_FREE_PAGES) / 2) { page = __rmqueue_cma_fallback(zone, order); @@ -2796,7 +2796,7 @@ __rmqueue(struct zone *zone, unsigned int order, int migratetype, retry: page = __rmqueue_smallest(zone, order, migratetype); if (unlikely(!page)) { - if (migratetype == MIGRATE_MOVABLE) + if (alloc_flags & ALLOC_CMA) page = __rmqueue_cma_fallback(zone, order); if (!page && __rmqueue_fallback(zone, order, migratetype, @@ -3687,6 +3687,20 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) return alloc_flags; } +static inline unsigned int current_alloc_flags(gfp_t gfp_mask, + unsigned int alloc_flags) +{ +#ifdef CONFIG_CMA + unsigned int pflags = current->flags; + + if (!(pflags & PF_MEMALLOC_NOCMA) && + gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) + alloc_flags |= ALLOC_CMA; + +#endif + return alloc_flags; +} + /* * get_page_from_freelist goes through the zonelist trying to allocate * a page. @@ -4333,10 +4347,8 @@ 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 + alloc_flags = current_alloc_flags(gfp_mask, alloc_flags); + return alloc_flags; } @@ -4637,7 +4649,7 @@ retry: reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); if (reserve_flags) - alloc_flags = reserve_flags; + alloc_flags = current_alloc_flags(gfp_mask, reserve_flags); /* * Reset the nodemask and zonelist iterators if memory policies can be @@ -4714,7 +4726,7 @@ retry: /* Avoid allocations with no watermarks from looping endlessly */ if (tsk_is_oom_victim(current) && - (alloc_flags == ALLOC_OOM || + (alloc_flags & ALLOC_OOM || (gfp_mask & __GFP_NOMEMALLOC))) goto nopage; @@ -4806,8 +4818,7 @@ 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; + *alloc_flags = current_alloc_flags(gfp_mask, *alloc_flags); return true; } |