[BUG] 2.6.26-rc5-mm2 - kernel BUG at arch/x86/kernel/setup.c:388!

["Vegard Nossum" <vegard.nossum@gmail.com>]

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On 6/9/08, Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> wrote:
> Hi Andrew,
>
> The 2.6.26-rc5-mm2 kernel panic's, while booting up on the x86_64
> box with the attached .config file.

(Please apologize for the strange way of replying to this message. It
seems that LKML gave up delivering to my address, so I'm currently
reading off lkml.org.)

This should already be fixed, but Andrew refused to apply the patch
before releasing the -mm1 (and -mm2 apparently). I'm attaching the
patch, can you see if it helps?

Thanks.


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036

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commit a953e4597abd51b74c99e0e3b7074532a60fd031
Author: Mike Travis <travis@sgi.com>
Date:   Mon May 12 21:21:12 2008 +0200

    sched: replace MAX_NUMNODES with nr_node_ids in kernel/sched.c
    
      * Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c,
        where appropriate.  This saves some allocated space as well as many
        wasted cycles going through node entries that are non-existent.
    
    For inclusion into sched-devel/latest tree.
    
    Based on:
    	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
        +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
    
    Signed-off-by: Mike Travis <travis@sgi.com>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index cfa222a..1ed8011 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6879,9 +6879,9 @@ static int find_next_best_node(int node, nodemask_t *used_nodes)
 
 	min_val = INT_MAX;
 
-	for (i = 0; i < MAX_NUMNODES; i++) {
+	for (i = 0; i < nr_node_ids; i++) {
 		/* Start at @node */
-		n = (node + i) % MAX_NUMNODES;
+		n = (node + i) % nr_node_ids;
 
 		if (!nr_cpus_node(n))
 			continue;
@@ -7075,7 +7075,7 @@ static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
 		if (!sched_group_nodes)
 			continue;
 
-		for (i = 0; i < MAX_NUMNODES; i++) {
+		for (i = 0; i < nr_node_ids; i++) {
 			struct sched_group *oldsg, *sg = sched_group_nodes[i];
 
 			*nodemask = node_to_cpumask(i);
@@ -7263,7 +7263,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 	/*
 	 * Allocate the per-node list of sched groups
 	 */
-	sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *),
+	sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
 				    GFP_KERNEL);
 	if (!sched_group_nodes) {
 		printk(KERN_WARNING "Can not alloc sched group node list\n");
@@ -7407,7 +7407,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 #endif
 
 	/* Set up physical groups */
-	for (i = 0; i < MAX_NUMNODES; i++) {
+	for (i = 0; i < nr_node_ids; i++) {
 		SCHED_CPUMASK_VAR(nodemask, allmasks);
 		SCHED_CPUMASK_VAR(send_covered, allmasks);
 
@@ -7431,7 +7431,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 					send_covered, tmpmask);
 	}
 
-	for (i = 0; i < MAX_NUMNODES; i++) {
+	for (i = 0; i < nr_node_ids; i++) {
 		/* Set up node groups */
 		struct sched_group *sg, *prev;
 		SCHED_CPUMASK_VAR(nodemask, allmasks);
@@ -7470,9 +7470,9 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 		cpus_or(*covered, *covered, *nodemask);
 		prev = sg;
 
-		for (j = 0; j < MAX_NUMNODES; j++) {
+		for (j = 0; j < nr_node_ids; j++) {
 			SCHED_CPUMASK_VAR(notcovered, allmasks);
-			int n = (i + j) % MAX_NUMNODES;
+			int n = (i + j) % nr_node_ids;
 			node_to_cpumask_ptr(pnodemask, n);
 
 			cpus_complement(*notcovered, *covered);
@@ -7525,7 +7525,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map,
 	}
 
 #ifdef CONFIG_NUMA
-	for (i = 0; i < MAX_NUMNODES; i++)
+	for (i = 0; i < nr_node_ids; i++)
 		init_numa_sched_groups_power(sched_group_nodes[i]);
 
 	if (sd_allnodes) {