Re: 2.6.38.3 and 2.6.39-rc4 hangs after "Booting the kernel" on quad Pentium Pro system

[Yinghai Lu <yinghai@kernel.org>]

On 04/22/2011 12:29 PM, Ingo Molnar wrote:
> 
> * Yinghai Lu <yinghai@kernel.org> wrote:
> 
>> with Chris's config for 2.6.39-rc4, current tip tree says:
>>
>> kernel/sched.c: In function ‘sched_init’:
>> kernel/sched.c:7845:28: error: ‘load_balance_tmpmask’ undeclared
>> (first use in this function)
>> kernel/sched.c:7845:28: note: each undeclared identifier is reported
>> only once for each function it appears in
>> kernel/sched.c:7845:3: warning: type defaults to ‘int’ in type name
>> kernel/sched.c:7845:28: warning: initialization makes pointer from
>> integer without a cast
>> kernel/sched.c:7845:3: warning: type defaults to ‘int’ in type name
> 
> Which sha1? It builds fine here on:
> 
>   ae1e16c: Merge branch 'perf/urgent'
> 

one local patch caused the problem.

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -7808,9 +7808,6 @@ void __init sched_init(void)
 #ifdef CONFIG_RT_GROUP_SCHED
 	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
 #endif
-#ifdef CONFIG_CPUMASK_OFFSTACK
-	alloc_size += num_possible_cpus() * cpumask_size();
-#endif
 	if (alloc_size) {
 		ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
 
@@ -7830,14 +7827,12 @@ void __init sched_init(void)
 		ptr += nr_cpu_ids * sizeof(void **);
 
 #endif /* CONFIG_RT_GROUP_SCHED */
-#ifdef CONFIG_CPUMASK_OFFSTACK
-		for_each_possible_cpu(i) {
-			per_cpu(load_balance_tmpmask, i) = (void *)ptr;
-			ptr += cpumask_size();
-		}
-#endif /* CONFIG_CPUMASK_OFFSTACK */
 	}
 
+	for_each_possible_cpu(i)
+		zalloc_cpumask_var_node(&per_cpu(load_balance_tmpmask, i),
+					GFP_NOWAIT, cpu_to_node(i));
+
 #ifdef CONFIG_SMP
 	init_defrootdomain();
 #endif


Sorry for noisy.

Thanks

Yinghai