On Wed, Sep 01, 2010 at 10:37:49AM +0900, KOSAKI Motohiro wrote: > When a page has PG_referenced, shrink_page_list() discard it only > if it is no dirty. This rule works completely fine if the backend > filesystem is regular one. PG_dirty is good signal that it was used > recently because flusher thread clean pages periodically. In addition, > page writeback is costly rather than simple page discard. > > However, When a page is on tmpfs, this heuristic don't works because > flusher thread don't writeback tmpfs pages. then, tmpfs pages always > rotate lru twice at least and it makes unnecessary lru churn. Merely > tmpfs streaming io shouldn't cause large anonymous page swap-out. > > This patch remove this unncessary reclaim bonus of tmpfs pages. > > Cc: Hugh Dickins <hughd@xxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxx> > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Reviewed-by: Johannes Weiner <hannes@xxxxxxxxxxx> > --- > mm/vmscan.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 1919d8a..aba3402 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -617,7 +617,7 @@ static enum page_references page_check_references(struct page *page, > } > > /* Reclaim if clean, defer dirty pages to writeback */ > - if (referenced_page) > + if (referenced_page && !PageSwapBacked(page)) > return PAGEREF_RECLAIM_CLEAN; > > return PAGEREF_RECLAIM; > -- > 1.6.5.2 > > > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>