From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
We have well defined scope API to exclude CMA region.
Use it rather than manipulating gfp_mask manually. With this change,
we can now restore __GFP_MOVABLE for gfp_mask like as usual migration
target allocation. It would result in that the ZONE_MOVABLE is also
searched by page allocator. For hugetlb, gfp_mask is redefined since
it has a regular allocation mask filter for migration target.
__GPF_NOWARN is added to hugetlb gfp_mask filter since a new user for
gfp_mask filter, gup, want to be silent when allocation fails.
Note that this can be considered as a fix for the commit 9a4e9f3b2d73
("mm: update get_user_pages_longterm to migrate pages allocated from
CMA region"). However, "Fixes" tag isn't added here since it is just
suboptimal but it doesn't cause any problem.
Suggested-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
include/linux/hugetlb.h | 2 ++
mm/gup.c | 17 ++++++++---------
2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 6b9508d..2660b04 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -708,6 +708,8 @@ static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
/* Some callers might want to enfoce node */
modified_mask |= (gfp_mask & __GFP_THISNODE);
+ modified_mask |= (gfp_mask & __GFP_NOWARN);
+
return modified_mask;
}
diff --git a/mm/gup.c b/mm/gup.c
index 5daadae..bbd36a1 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1619,10 +1619,12 @@ static struct page *new_non_cma_page(struct page *page, unsigned long private)
* Trying to allocate a page for migration. Ignore allocation
* failure warnings. We don't force __GFP_THISNODE here because
* this node here is the node where we have CMA reservation and
- * in some case these nodes will have really less non movable
+ * in some case these nodes will have really less non CMA
* allocation memory.
+ *
+ * Note that CMA region is prohibited by allocation scope.
*/
- gfp_t gfp_mask = GFP_USER | __GFP_NOWARN;
+ gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_NOWARN;
if (PageHighMem(page))
gfp_mask |= __GFP_HIGHMEM;
@@ -1630,6 +1632,8 @@ static struct page *new_non_cma_page(struct page *page, unsigned long private)
#ifdef CONFIG_HUGETLB_PAGE
if (PageHuge(page)) {
struct hstate *h = page_hstate(page);
+
+ gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
/*
* We don't want to dequeue from the pool because pool pages will
* mostly be from the CMA region.
@@ -1644,11 +1648,6 @@ static struct page *new_non_cma_page(struct page *page, unsigned long private)
*/
gfp_t thp_gfpmask = GFP_TRANSHUGE | __GFP_NOWARN;
- /*
- * Remove the movable mask so that we don't allocate from
- * CMA area again.
- */
- thp_gfpmask &= ~__GFP_MOVABLE;
thp = __alloc_pages_node(nid, thp_gfpmask, HPAGE_PMD_ORDER);
if (!thp)
return NULL;
@@ -1794,7 +1793,6 @@ static long __gup_longterm_locked(struct task_struct *tsk,
vmas_tmp, NULL, gup_flags);
if (gup_flags & FOLL_LONGTERM) {
- memalloc_nocma_restore(flags);
if (rc < 0)
goto out;
@@ -1807,9 +1805,10 @@ static long __gup_longterm_locked(struct task_struct *tsk,
rc = check_and_migrate_cma_pages(tsk, mm, start, rc, pages,
vmas_tmp, gup_flags);
+out:
+ memalloc_nocma_restore(flags);
}
-out:
if (vmas_tmp != vmas)
kfree(vmas_tmp);
return rc;
--
2.7.4
