From c3e58a70425ac6ddaae1529c8146e88b4f7252bb Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Fri, 18 Nov 2022 10:17:13 +0000 Subject: mm/page_alloc: always remove pages from temporary list Patch series "Leave IRQs enabled for per-cpu page allocations", v3. This patch (of 2): free_unref_page_list() has neglected to remove pages properly from the list of pages to free since forever. It works by coincidence because list_add happened to do the right thing adding the pages to just the PCP lists. However, a later patch added pages to either the PCP list or the zone list but only properly deleted the page from the list in one path leading to list corruption and a subsequent failure. As a preparation patch, always delete the pages from one list properly before adding to another. On its own, this fixes nothing although it adds a fractional amount of overhead but is critical to the next patch. Link: https://lkml.kernel.org/r/20221118101714.19590-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20221118101714.19590-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman Reported-by: Hugh Dickins Reviewed-by: Vlastimil Babka Cc: Marcelo Tosatti Cc: Marek Szyprowski Cc: Michal Hocko Cc: Yu Zhao Signed-off-by: Andrew Morton --- mm/page_alloc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c33b6963c2d7..ca889fb53cbb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3553,6 +3553,8 @@ void free_unref_page_list(struct list_head *list) list_for_each_entry_safe(page, next, list, lru) { struct zone *zone = page_zone(page); + list_del(&page->lru); + /* Different zone, different pcp lock. */ if (zone != locked_zone) { if (pcp) -- cgit v1.2.3