From: Nicholas Piggin <npiggin@xxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxxxxxxxx: fix -stat.nr_lazyfree_fail as well, per Michal]
Link: https://lkml.kernel.org/r/20201029032320.1448441-1-npiggin@xxxxxxxxx
Fixes: 730ec8c01a2b ("mm/vmscan.c: change prototype for shrink_page_list")
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vaneet Narang <v.narang@xxxxxxxxxxx>
Cc: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Cc: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/vmscan.c~mm-vmscan-fix-nr_isolated_file-corruption-on-64-bit
+++ a/mm/vmscan.c
@@ -1516,7 +1516,8 @@ unsigned int reclaim_clean_pages_from_li
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_li
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;
}
_
