On Tue, Sep 04, 2012 at 03:26:22PM +0200, Bartlomiej Zolnierkiewicz wrote: > Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter. > Fix it by properly decreasing/increasing NR_FREE_PAGES counter in > set_migratetype_isolate()/unset_migratetype_isolate() and removing > counter adjustment for isolated pages from free_one_page() and > split_free_page(). > > Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Cc: Michal Nazarewicz <mina86@xxxxxxxxxx> > Cc: Minchan Kim <minchan@xxxxxxxxxx> > Cc: Mel Gorman <mgorman@xxxxxxx> > Cc: Hugh Dickins <hughd@xxxxxxxxxx> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > --- > mm/page_alloc.c | 7 +++++-- > mm/page_isolation.c | 13 ++++++++++--- > 2 files changed, 15 insertions(+), 5 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index e9da55c..3acdf0f 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -691,7 +691,8 @@ static void free_one_page(struct zone *zone, struct page *page, int order, > zone->pages_scanned = 0; > > __free_one_page(page, zone, order, migratetype); > - __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); > + if (migratetype != MIGRATE_ISOLATE) We can add unlikely. > + __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); > spin_unlock(&zone->lock); > } > > @@ -1414,7 +1415,9 @@ int split_free_page(struct page *page, bool check_wmark) > list_del(&page->lru); > zone->free_area[order].nr_free--; > rmv_page_order(page); > - __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); > + > + if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) The get_pageblock_migratetype isn't cheap. You can use get_freepage_migratetype. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>