[PATCH 1/1] sched: remove unnecessary kzalloc in sched_init_smp

From: Mike Travis
Date: Tue Apr 22 2008 - 13:04:44 EST


Tony Luck wrote:
> On Fri, Apr 4, 2008 at 6:11 PM, Mike Travis <travis@xxxxxxx> wrote:
>> @@ -7297,6 +7287,11 @@ void __init sched_init_smp(void)
>> #else
>> void __init sched_init_smp(void)
>> {
>> +#if defined(CONFIG_NUMA)
>> + sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
>> + GFP_KERNEL);
>> + BUG_ON(sched_group_nodes_bycpu == NULL);
>> +#endif
>> sched_init_granularity();
>> }
>> #endif /* CONFIG_SMP */
>
> This hunk is causing problems with one of my builds (generic,
> uniprocessor). Note
> that the #else at the start of this hunk is from a #ifdef CONFIG_SMP ... so I'm
> wondering why we need #if defined(CONFIG_NUMA) inside uniprocessor code :-)
> How can you have NUMA issues with only one cpu!!!

>>> CONFIG_NUMA is dependent on CONFIG_SMP for x86 so that caused me to miss
>>> the error. But here's the fix:

* sched_group_nodes_bycpu is defined only for the SMP + NUMA case,
it should not be referenced in the !SMP + NUMA case.

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@xxxxxxx>
---
kernel/sched.c | 5 -----
1 file changed, 5 deletions(-)

--- linux-2.6.sched.orig/kernel/sched.c
+++ linux-2.6.sched/kernel/sched.c
@@ -8028,11 +8028,6 @@ void __init sched_init_smp(void)
#else
void __init sched_init_smp(void)
{
-#if defined(CONFIG_NUMA)
- sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
- GFP_KERNEL);
- BUG_ON(sched_group_nodes_bycpu == NULL);
-#endif
sched_init_granularity();
}
#endif /* CONFIG_SMP */
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