On Thu 29-10-20 13:23:20, Nicholas Piggin wrote: > 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)))". Nasty. > Cc: linux-mm@xxxxxxxxx > Cc: Maninder Singh <maninder1.s@xxxxxxxxxxx> > Cc: Vaneet Narang <v.narang@xxxxxxxxxxx> > Cc: Maninder Singh <maninder1.s@xxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx> > Cc: Mel Gorman <mgorman@xxxxxxx> > Cc: Vlastimil Babka <vbabka@xxxxxxx> > Fixes: 730ec8c01a2b ("mm/vmscan.c: change prototype for shrink_page_list") > Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx> > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 1b8f0e059767..92c507bacf09 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1516,7 +1516,7 @@ 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 You want the same also for -stat.nr_lazyfree_fail right? -- Michal Hocko SUSE Labs