Commit 4cf808eb authored by Linus Torvalds's avatar Linus Torvalds Committed by Linus Torvalds
Browse files

[PATCH] Handle holes in node mask in node fallback list setup 



Change the find_next_best_node algorithm to correctly skip
over holes in the node online mask. Previously it would not handle
missing nodes correctly and cause crashes at boot.

[Written by Linus, tested by AK]

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent cfe91f9c

mm/page_alloc.c

+11 −11
Original line number Diff line number Diff line
@@ -1541,29 +1541,29 @@ static int __initdata node_load[MAX_NUMNODES]; 
 */

static int __init find_next_best_node(int node, nodemask_t *used_node_mask)

{

	int i, n, val;

	int n, val;

	int min_val = INT_MAX;

	int best_node = -1;



	for_each_online_node(i) {

		cpumask_t tmp;

	/* Use the local node if we haven't already */

	if (!node_isset(node, *used_node_mask)) {

		node_set(node, *used_node_mask);

		return node;

	}



		/* Start from local node */

		n = (node+i) % num_online_nodes();

	for_each_online_node(n) {

		cpumask_t tmp;



		/* Don't want a node to appear more than once */

		if (node_isset(n, *used_node_mask))

			continue;



		/* Use the local node if we haven't already */

		if (!node_isset(node, *used_node_mask)) {

			best_node = node;

			break;

		}



		/* Use the distance array to find the distance */

		val = node_distance(node, n);



		/* Penalize nodes under us ("prefer the next node") */

		val += (n < node);



		/* Give preference to headless and unused nodes */

		tmp = node_to_cpumask(n);

		if (!cpus_empty(tmp))