Re: [PATCH] sched isolcpus=1 related OOPS in 2.6.9

[devik]

> You are correct, of course.  If "isolcpus" is used, the isolated
> cpu(s) (in <cpu_isolated_map>) are not init like the remaining
> cpus are.
>
> I don't know what's intended here... but it's not the divide by 0.

A patch is attached which fixes problems with isolated
domains for me. I hope it is correct :-) I will try on
real SMP when I will be in work (now it boots on Boochs).

enjoy,

    Martin Devera aka devik
Linux kernel QoS/HTB maintainer
  http://luxik.cdi.cz/~devik/
--- linux-2.6.9/kernel/sched.c	Mon Oct 18 23:54:55 2004
+++ kernel/sched.c	Fri Dec  3 19:06:04 2004
@@ -4480,7 +4480,7 @@
 #ifdef CONFIG_NUMA
 		sd->span = nodemask;
 #else
-		sd->span = cpu_possible_map;
+		sd->span = cpu_default_map;
 #endif
 		sd->parent = p;
 		sd->groups = &sched_group_phys[group];
@@ -4512,11 +4512,14 @@
 
 	/* Set up isolated groups */
 	for_each_cpu_mask(i, cpu_isolated_map) {
+		int group;
 		cpumask_t mask;
 		cpus_clear(mask);
 		cpu_set(i, mask);
 		init_sched_build_groups(sched_group_isolated, mask,
 						&cpu_to_isolated_group);
+		group = cpu_to_isolated_group(i);
+		sched_group_isolated[group].cpu_power = SCHED_LOAD_SCALE;
 	}
 
 #ifdef CONFIG_NUMA
@@ -4532,7 +4535,7 @@
 						&cpu_to_phys_group);
 	}
 #else
-	init_sched_build_groups(sched_group_phys, cpu_possible_map,
+	init_sched_build_groups(sched_group_phys, cpu_default_map,
 							&cpu_to_phys_group);
 #endif
 
@@ -4634,7 +4637,7 @@
 				cpus_or(groupmask, groupmask, group->cpumask);
 
 				cpumask_scnprintf(str, NR_CPUS, group->cpumask);
-				printk(" %s", str);
+				printk(" %s[%ld]", str, group->cpu_power);
 
 				group = group->next;
 			} while (group != sd->groups);