[PATCH 4/5] mm/migrate.c: use helper migrate_vma_collect_skip() in migrate_vma_collect_hole()

Miaohe Lin
2021-03-20T09:38:05Z

It's more recommended to use helper function migrate_vma_collect_skip() to
skip the unexpected case and it also helps remove some duplicated codes.
Move migrate_vma_collect_skip() above migrate_vma_collect_hole() to avoid
compiler warning.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/migrate.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 271081b014cb..3e169b72d7b2 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2315,44 +2315,38 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
#endif /* CONFIG_NUMA */

#ifdef CONFIG_DEVICE_PRIVATE
-static int migrate_vma_collect_hole(unsigned long start,
+static int migrate_vma_collect_skip(unsigned long start,
unsigned long end,
- __always_unused int depth,
struct mm_walk *walk)
{
struct migrate_vma *migrate = walk->private;
unsigned long addr;

- /* Only allow populating anonymous memory. */
- if (!vma_is_anonymous(walk->vma)) {
- for (addr = start; addr < end; addr += PAGE_SIZE) {
- migrate->src[migrate->npages] = 0;
- migrate->dst[migrate->npages] = 0;
- migrate->npages++;
- }
- return 0;
- }
-
for (addr = start; addr < end; addr += PAGE_SIZE) {
- migrate->src[migrate->npages] = MIGRATE_PFN_MIGRATE;
migrate->dst[migrate->npages] = 0;
- migrate->npages++;
- migrate->cpages++;
+ migrate->src[migrate->npages++] = 0;
}

return 0;
}

-static int migrate_vma_collect_skip(unsigned long start,
+static int migrate_vma_collect_hole(unsigned long start,
unsigned long end,
+ __always_unused int depth,
struct mm_walk *walk)
{
struct migrate_vma *migrate = walk->private;
unsigned long addr;

+ /* Only allow populating anonymous memory. */
+ if (!vma_is_anonymous(walk->vma))
+ return migrate_vma_collect_skip(start, end, walk);
+
for (addr = start; addr < end; addr += PAGE_SIZE) {
+ migrate->src[migrate->npages] = MIGRATE_PFN_MIGRATE;
migrate->dst[migrate->npages] = 0;
- migrate->src[migrate->npages++] = 0;
+ migrate->npages++;
+ migrate->cpages++;
}

return 0;
--
2.19.1