path: root/include/linux/sched
diff options
authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2020-08-06 23:26:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:29 -0700
commit8510e69c8efef82f2b37ea3e8ea19a27122c533e (patch)
tree41e4a0fc437e4e723bece37ca7ebc8005c26c68f /include/linux/sched
parent182f3d7a02fddd9e4b1181c2ba710a930e05ddbb (diff)
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 'include/linux/sched')
1 files changed, 1 insertions, 7 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 6be66f52a2ad..85023ddc2dc2 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -175,12 +175,10 @@ static inline bool in_vfork(struct task_struct *tsk)
* Applies per-task gfp context to the given allocation flags.
- * PF_MEMALLOC_NOCMA implies no allocation from CMA region.
static inline gfp_t current_gfp_context(gfp_t flags)
- if (unlikely(current->flags &
+ 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
@@ -189,10 +187,6 @@ static inline gfp_t current_gfp_context(gfp_t flags)
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;
return flags;