From: Doug Berger <opendmb@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Doug Berger <opendmb@gmail.com>
Subject: [PATCH] mm/page_alloc: don't corrupt pcppage_migratetype
Date: Wed, 11 Aug 2021 11:29:17 -0700 [thread overview]
Message-ID: <20210811182917.2607994-1-opendmb@gmail.com> (raw)
When placing pages on a pcp list, migratetype values over
MIGRATE_PCPTYPES get added to the MIGRATE_MOVABLE pcp list.
However, the actual migratetype is preserved in the page and
should not be changed to MIGRATE_MOVABLE or the page may end
up on the wrong free_list.
Fixes: df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Doug Berger <opendmb@gmail.com>
---
mm/page_alloc.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 73704e836649..8addb4919f75 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3436,19 +3436,10 @@ void free_unref_page_list(struct list_head *list)
* comment in free_unref_page.
*/
migratetype = get_pcppage_migratetype(page);
- if (unlikely(migratetype >= MIGRATE_PCPTYPES)) {
- if (unlikely(is_migrate_isolate(migratetype))) {
- list_del(&page->lru);
- free_one_page(page_zone(page), page, pfn, 0,
- migratetype, FPI_NONE);
- continue;
- }
-
- /*
- * Non-isolated types over MIGRATE_PCPTYPES get added
- * to the MIGRATE_MOVABLE pcp list.
- */
- set_pcppage_migratetype(page, MIGRATE_MOVABLE);
+ if (unlikely(is_migrate_isolate(migratetype))) {
+ list_del(&page->lru);
+ free_one_page(page_zone(page), page, pfn, 0, migratetype, FPI_NONE);
+ continue;
}
set_page_private(page, pfn);
@@ -3458,7 +3449,15 @@ void free_unref_page_list(struct list_head *list)
list_for_each_entry_safe(page, next, list, lru) {
pfn = page_private(page);
set_page_private(page, 0);
+
+ /*
+ * Non-isolated types over MIGRATE_PCPTYPES get added
+ * to the MIGRATE_MOVABLE pcp list.
+ */
migratetype = get_pcppage_migratetype(page);
+ if (unlikely(migratetype >= MIGRATE_PCPTYPES))
+ migratetype = MIGRATE_MOVABLE;
+
trace_mm_page_free_batched(page);
free_unref_page_commit(page, pfn, migratetype, 0);
--
2.25.1
next reply other threads:[~2021-08-11 18:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 18:29 Doug Berger [this message]
2021-08-12 8:17 ` [PATCH] mm/page_alloc: don't corrupt pcppage_migratetype Vlastimil Babka
2021-08-13 0:21 ` Doug Berger
2021-08-19 13:09 ` Vlastimil Babka
2021-08-12 10:56 ` Mel Gorman
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