The patch titled Subject: mm/page_alloc: fix memalloc_nocma_{save/restore} APIs has been added to the -mm tree. Its filename is mm-page_alloc-fix-memalloc_nocma_save-restore-apis.patch
This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-fix-memalloc_nocma_sa... and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-fix-memalloc_nocma_sa...
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------------------------------------------------------ From: js1304@gmail.com Subject: 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.
Link: http://lkml.kernel.org/r/1595468942-29687-1-git-send-email-iamjoonsoo.kim@lg... Fixes: d7fefcc8de91 (mm/cma: add PF flag to force non cma alloc) Signed-off-by: Joonsoo Kim iamjoonsoo.kim@lge.com 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 Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
include/linux/sched/mm.h | 8 +------- mm/page_alloc.c | 31 +++++++++++++++++++++---------- 2 files changed, 22 insertions(+), 17 deletions(-)
--- a/include/linux/sched/mm.h~mm-page_alloc-fix-memalloc_nocma_save-restore-apis +++ a/include/linux/sched/mm.h @@ -177,12 +177,10 @@ static inline bool in_vfork(struct task_ * Applies per-task gfp context to the given allocation flags. * PF_MEMALLOC_NOIO implies GFP_NOIO * PF_MEMALLOC_NOFS implies GFP_NOFS - * PF_MEMALLOC_NOCMA implies no allocation from CMA region. */ static inline gfp_t current_gfp_context(gfp_t flags) { - if (unlikely(current->flags & - (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA))) { + if (unlikely(current->flags & (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS))) { /* * NOIO implies both NOIO and NOFS and it is a weaker context * so always make sure it makes precedence @@ -191,10 +189,6 @@ static inline gfp_t current_gfp_context( flags &= ~(__GFP_IO | __GFP_FS); else if (current->flags & PF_MEMALLOC_NOFS) flags &= ~__GFP_FS; -#ifdef CONFIG_CMA - if (current->flags & PF_MEMALLOC_NOCMA) - flags &= ~__GFP_MOVABLE; -#endif } return flags; } --- a/mm/page_alloc.c~mm-page_alloc-fix-memalloc_nocma_save-restore-apis +++ a/mm/page_alloc.c @@ -2790,7 +2790,7 @@ __rmqueue(struct zone *zone, unsigned in * 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); @@ -2801,7 +2801,7 @@ __rmqueue(struct zone *zone, unsigned in 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, @@ -3671,6 +3671,20 @@ alloc_flags_nofragment(struct zone *zone 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. @@ -4316,10 +4330,8 @@ 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; }
@@ -4620,7 +4632,7 @@ 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 @@ -4697,7 +4709,7 @@ 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;
@@ -4785,8 +4797,7 @@ static inline bool prepare_alloc_pages(g 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; } _
Patches currently in -mm which might be from iamjoonsoo.kim@lge.com are
mm-page_alloc-fix-memalloc_nocma_save-restore-apis.patch mm-vmscan-make-active-inactive-ratio-as-1-1-for-anon-lru.patch mm-vmscan-protect-the-workingset-on-anonymous-lru.patch mm-workingset-prepare-the-workingset-detection-infrastructure-for-anon-lru.patch mm-swapcache-support-to-handle-the-shadow-entries.patch mm-swap-implement-workingset-detection-for-anonymous-lru.patch mm-vmscan-restore-active-inactive-ratio-for-anonymous-lru.patch mm-page_isolation-prefer-the-node-of-the-source-page.patch mm-migrate-move-migration-helper-from-h-to-c.patch mm-hugetlb-unify-migration-callbacks.patch mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations.patch mm-migrate-make-a-standard-migration-target-allocation-function.patch mm-mempolicy-use-a-standard-migration-target-allocation-callback.patch mm-page_alloc-remove-a-wrapper-for-alloc_migration_target.patch mm-memory-failure-remove-a-wrapper-for-alloc_migration_target.patch mm-memory_hotplug-remove-a-wrapper-for-alloc_migration_target.patch