cma: decrease cc.nr_migratepages after reclaiming pagelist

reclaim_clean_pages_from_list() reclaims clean pages before migration so
cc.nr_migratepages should be updated.  Currently, there is no problem but
it can be wrong if we try to use the value in future.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ddc155300a67e512f047d2fd0feb746dfdcd0972..8e1be1c4bbbf9193c972207f21d8e27952899d1a 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5672,7 +5672,7 @@ static unsigned long pfn_max_align_up(unsigned long pfn)
 static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
 {
        /* This function is based on compact_zone() from compaction.c. */
-
+       unsigned long nr_reclaimed;
        unsigned long pfn = start;
        unsigned int tries = 0;
        int ret = 0;
@@ -5708,7 +5708,9 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
                        break;
                }
 
-               reclaim_clean_pages_from_list(cc.zone, &cc.migratepages);
+               nr_reclaimed = reclaim_clean_pages_from_list(cc.zone,
+                                                       &cc.migratepages);
+               cc.nr_migratepages -= nr_reclaimed;
 
                ret = migrate_pages(&cc.migratepages,
                                    alloc_migrate_target,