[PATCH v2 10/12] mm/gup: use standard migration target allocation function

From: js1304
Date: Wed May 27 2020 - 02:46:19 EST


From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

There is no reason to implement it's own function for migration
target allocation. Use standard one.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
mm/gup.c | 61 ++++++++++---------------------------------------------------
1 file changed, 10 insertions(+), 51 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index a49d7ea..0e4214d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1593,58 +1593,16 @@ static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages)
}

#ifdef CONFIG_CMA
-static struct page *new_non_cma_page(struct page *page,
+static struct page *alloc_migration_target_non_cma(struct page *page,
struct alloc_control *ac)
{
- /*
- * We want to make sure we allocate the new page from the same node
- * as the source page.
- */
- int nid = page_to_nid(page);
- /*
- * 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
- * allocation memory.
- */
- gfp_t gfp_mask = GFP_USER | __GFP_NOWARN;
-
- if (PageHighMem(page))
- gfp_mask |= __GFP_HIGHMEM;
-
- if (PageHuge(page)) {
- struct hstate *h = page_hstate(page);
- struct alloc_control ac = {
- .nid = nid,
- .nmask = NULL,
- .gfp_mask = __GFP_NOWARN,
- .skip_cma = true,
- };
-
- return alloc_huge_page_nodemask(h, &ac);
- }
-
- if (PageTransHuge(page)) {
- struct page *thp;
- /*
- * ignore allocation failure warnings
- */
- 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;
- prep_transhuge_page(thp);
- return thp;
- }
+ struct alloc_control __ac = {
+ .nid = page_to_nid(page),
+ .gfp_mask = GFP_USER | __GFP_NOWARN,
+ .skip_cma = true,
+ };

- return __alloc_pages_node(nid, gfp_mask, 0);
+ return alloc_migration_target(page, &__ac);
}

static long check_and_migrate_cma_pages(struct task_struct *tsk,
@@ -1706,8 +1664,9 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk,
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);

- if (migrate_pages(&cma_page_list, new_non_cma_page,
- NULL, NULL, MIGRATE_SYNC, MR_CONTIG_RANGE)) {
+ if (migrate_pages(&cma_page_list,
+ alloc_migration_target_non_cma, NULL, NULL,
+ MIGRATE_SYNC, MR_CONTIG_RANGE)) {
/*
* some of the pages failed migration. Do get_user_pages
* without migration.
--
2.7.4