linux-kernel - [PATCH 3/6] mm: page_alloc: move free pages when converting block during isolation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230911195023.247694-4-hannes@cmpxchg.org>
Date:   Mon, 11 Sep 2023 15:41:44 -0400
From:   Johannes Weiner <hannes@...xchg.org>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Vlastimil Babka <vbabka@...e.cz>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Zi Yan <ziy@...dia.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 3/6] mm: page_alloc: move free pages when converting block during isolation

When claiming a block during compaction isolation, move any remaining
free pages to the correct freelists as well, instead of stranding them
on the wrong list. Otherwise, this encourages incompatible page mixing
down the line, and thus long-term fragmentation.

Signed-off-by: Johannes Weiner <hannes@...xchg.org>
---
 mm/page_alloc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3db405414174..f6f658c3d394 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2548,9 +2548,12 @@ int __isolate_free_page(struct page *page, unsigned int order)
 			 * Only change normal pageblocks (i.e., they can merge
 			 * with others)
 			 */
-			if (migratetype_is_mergeable(mt))
+			if (migratetype_is_mergeable(mt)) {
 				set_pageblock_migratetype(page,
 							  MIGRATE_MOVABLE);
+				move_freepages_block(zone, page,
+						     MIGRATE_MOVABLE, NULL);
+			}
 		}
 	}
 
-- 
2.42.0