From 2da9f6305f306ffbbb44790675799328fb73119d Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 13 Nov 2020 22:51:46 -0800 Subject: [PATCH] mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit Previously the negated unsigned long would be cast back to signed long which would have the correct negative value. After commit 730ec8c01a2b ("mm/vmscan.c: change prototype for shrink_page_list"), the large unsigned int converts to a large positive signed long. Symptoms include CMA allocations hanging forever holding the cma_mutex due to alloc_contig_range->...->isolate_migratepages_block waiting forever in "while (unlikely(too_many_isolated(pgdat)))". [akpm@linux-foundation.org: fix -stat.nr_lazyfree_fail as well, per Michal] Fixes: 730ec8c01a2b ("mm/vmscan.c: change prototype for shrink_page_list") Signed-off-by: Nicholas Piggin Signed-off-by: Andrew Morton Acked-by: Michal Hocko Cc: Vaneet Narang Cc: Maninder Singh Cc: Amit Sahrawat Cc: Mel Gorman Cc: Vlastimil Babka Cc: Link: https://lkml.kernel.org/r/20201029032320.1448441-1-npiggin@gmail.com Signed-off-by: Linus Torvalds --- mm/vmscan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 1b8f0e059767..7b4e31eac2cf 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1516,7 +1516,8 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone, nr_reclaimed = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc, TTU_IGNORE_ACCESS, &stat, true); list_splice(&clean_pages, page_list); - mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, -nr_reclaimed); + mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, + -(long)nr_reclaimed); /* * Since lazyfree pages are isolated from file LRU from the beginning, * they will rotate back to anonymous LRU in the end if it failed to @@ -1526,7 +1527,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone, mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_ANON, stat.nr_lazyfree_fail); mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, - -stat.nr_lazyfree_fail); + -(long)stat.nr_lazyfree_fail); return nr_reclaimed; }