On Fri, Dec 13, 2013 at 02:10:03PM +0000, Mel Gorman wrote: > zone_local is using node_distance which is a more expensive call than > necessary. On x86, it's another function call in the allocator fast path > and increases cache footprint. This patch makes the assumption zones on a > local node will share the same node ID. The necessary information should > already be cache hot. > > Signed-off-by: Mel Gorman <[email protected]> > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 64020eb..fd9677e 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1816,7 +1816,7 @@ static void zlc_clear_zones_full(struct zonelist > *zonelist) > > static bool zone_local(struct zone *local_zone, struct zone *zone) > { > - return node_distance(local_zone->node, zone->node) == LOCAL_DISTANCE; > + return zone_to_nid(zone) == numa_node_id();
Why numa_node_id()? We pass in the preferred zone as @local_zone: return zone_to_nid(local_zone) == zone_to_nid(zone) Or even just compare the ->zone_pgdat pointers? -- 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/
