From 523b945855a1427000ffc707c610abe5947ae607 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 16 Oct 2007 01:25:37 -0700 Subject: Memoryless nodes: Fix GFP_THISNODE behavior GFP_THISNODE checks that the zone selected is within the pgdat (node) of the first zone of a nodelist. That only works if the node has memory. A memoryless node will have its first node on another pgdat (node). GFP_THISNODE currently will return simply memory on the first pgdat. Thus it is returning memory on other nodes. GFP_THISNODE should fail if there is no local memory on a node. Add a new set of zonelists for each node that only contain the nodes that belong to the zones itself so that no fallback is possible. Then modify gfp_type to pickup the right zone based on the presence of __GFP_THISNODE. Drop the existing GFP_THISNODE checks from the page_allocators hot path. Signed-off-by: Christoph Lameter Acked-by: Nishanth Aravamudan Tested-by: Lee Schermerhorn Acked-by: Bob Picco Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d06f6e0f75a..2f547f45de1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1191,9 +1191,6 @@ zonelist_scan: !zlc_zone_worth_trying(zonelist, z, allowednodes)) continue; zone = *z; - if (unlikely(NUMA_BUILD && (gfp_mask & __GFP_THISNODE) && - zone->zone_pgdat != zonelist->zones[0]->zone_pgdat)) - break; if ((alloc_flags & ALLOC_CPUSET) && !cpuset_zone_allowed_softwall(zone, gfp_mask)) goto try_next_zone; @@ -1262,7 +1259,10 @@ restart: z = zonelist->zones; /* the list of zones suitable for gfp_mask */ if (unlikely(*z == NULL)) { - /* Should this ever happen?? */ + /* + * Happens if we have an empty zonelist as a result of + * GFP_THISNODE being used on a memoryless node + */ return NULL; } @@ -1857,6 +1857,22 @@ static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) } } +/* + * Build gfp_thisnode zonelists + */ +static void build_thisnode_zonelists(pg_data_t *pgdat) +{ + enum zone_type i; + int j; + struct zonelist *zonelist; + + for (i = 0; i < MAX_NR_ZONES; i++) { + zonelist = pgdat->node_zonelists + MAX_NR_ZONES + i; + j = build_zonelists_node(pgdat, zonelist, 0, i); + zonelist->zones[j] = NULL; + } +} + /* * Build zonelists ordered by zone and nodes within zones. * This results in conserving DMA zone[s] until all Normal memory is @@ -1961,7 +1977,7 @@ static void build_zonelists(pg_data_t *pgdat) int order = current_zonelist_order; /* initialize zonelists */ - for (i = 0; i < MAX_NR_ZONES; i++) { + for (i = 0; i < MAX_ZONELISTS; i++) { zonelist = pgdat->node_zonelists + i; zonelist->zones[0] = NULL; } @@ -2006,6 +2022,8 @@ static void build_zonelists(pg_data_t *pgdat) /* calculate node order -- i.e., DMA last! */ build_zonelists_in_zone_order(pgdat, j); } + + build_thisnode_zonelists(pgdat); } /* Construct the zonelist performance cache - see further mmzone.h */ -- cgit v1.2.3