On Sun 17-03-13 13:04:11, Mel Gorman wrote: > Page reclaim at priority 0 will scan the entire LRU as priority 0 is > considered to be a near OOM condition. Kswapd can reach priority 0 quite > easily if it is encountering a large number of pages it cannot reclaim > such as pages under writeback. When this happens, kswapd reclaims very > aggressively even though there may be no real risk of allocation failure > or OOM. > > This patch prevents kswapd reaching priority 0 and trying to reclaim > the world. Direct reclaimers will still reach priority 0 in the event > of an OOM situation.
OK, it should work. raise_priority should prevent from pointless lowerinng the priority and if there is really nothing to reclaim then relying on the direct reclaim is probably a better idea. > Signed-off-by: Mel Gorman <[email protected]> Reviewed-by: Michal Hocko <[email protected]> > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 7513bd1..af3bb6f 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2891,7 +2891,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, > int order, > */ > if (raise_priority || !this_reclaimed) > sc.priority--; > - } while (sc.priority >= 0 && > + } while (sc.priority >= 1 && > !pgdat_balanced(pgdat, order, *classzone_idx)); > > out: > -- > 1.8.1.4 > -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
