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authorHuang Ying <ying.huang@intel.com>2022-08-17 16:14:06 +0800
committerAndrew Morton <akpm@linux-foundation.org>2022-09-26 19:46:07 -0700
commite6fa8a79fe03e1734c26287474b1ac09287fdeb7 (patch)
tree69844056e1eac50a2cb544f001956962fb1129be /mm/migrate.c
parent577be05c8927aa593cf7e29e2b4940607f5756ff (diff)
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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/20220817081408.513338-7-ying.huang@intel.com Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Zi Yan <ziy@nvidia.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
-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++;