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authorHuang Ying <[email protected]>2022-08-17 16:14:06 +0800
committerAndrew Morton <[email protected]>2022-09-26 19:46:07 -0700
commite6fa8a79fe03e1734c26287474b1ac09287fdeb7 (patch)
tree69844056e1eac50a2cb544f001956962fb1129be
parent577be05c8927aa593cf7e29e2b4940607f5756ff (diff)
migrate_pages(): fix failure counting for THP splitting
If THP is failed to be migrated, it may be split and retry. But after splitting, the head page will be left in "from" list, although THP migration failure has been counted already. If the head page is failed to be migrated too, the failure will be counted twice incorrectly. So this is fixed in this patch via moving the head page of THP after splitting to "thp_split_pages" too. Link: https://lkml.kernel.org/r/[email protected] Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") Signed-off-by: "Huang, Ying" <[email protected]> Reviewed-by: Baolin Wang <[email protected]> Reviewed-by: Oscar Salvador <[email protected]> Cc: Zi Yan <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
-rw-r--r--mm/migrate.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 0223673e42d1..81daa4dd3bb6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1374,6 +1374,8 @@ static inline int try_split_thp(struct page *page, struct list_head *split_pages
lock_page(page);
rc = split_huge_page_to_list(page, split_pages);
unlock_page(page);
+ if (!rc)
+ list_move_tail(&page->lru, split_pages);
return rc;
}
@@ -1433,7 +1435,6 @@ thp_subpage_migration:
thp_retry = 0;
list_for_each_entry_safe(page, page2, from, lru) {
-retry:
/*
* THP statistics is based on the source huge page.
* Capture required information that might get lost
@@ -1469,10 +1470,9 @@ retry:
* retry on the same page with the THP split
* to base pages.
*
- * Head page is retried immediately and tail
- * pages are added to the tail of the list so
- * we encounter them after the rest of the list
- * is processed.
+ * Sub-pages are put in thp_split_pages, and
+ * we will migrate them after the rest of the
+ * list is processed.
*/
case -ENOSYS:
/* THP migration is unsupported */
@@ -1480,7 +1480,7 @@ retry:
nr_thp_failed++;
if (!try_split_thp(page, &thp_split_pages)) {
nr_thp_split++;
- goto retry;
+ break;
}
/* Hugetlb migration is unsupported */
} else if (!no_subpage_counting) {
@@ -1500,7 +1500,7 @@ retry:
/* THP NUMA faulting doesn't split THP to retry. */
if (!nosplit && !try_split_thp(page, &thp_split_pages)) {
nr_thp_split++;
- goto retry;
+ break;
}
} else if (!no_subpage_counting) {
nr_failed++;