[PATCH] sched: zalloc most of the cpu masks

From: Rusty Russell
Date: Mon Nov 02 2009 - 05:08:33 EST


I got a boot crash when forcing cpumasks offstack on 32 bit, because
find_new_ilb() returned 3 on my UP system (nohz.cpu_mask wasn't zeroed).

AFAICT the others need to be zeroed too: only nohz.ilb_grp_nohz_mask is
initialized before use.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
kernel/sched.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9532,13 +9541,13 @@ void __init sched_init(void)
current->sched_class = &fair_sched_class;

/* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
- alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
+ zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
#ifdef CONFIG_SMP
#ifdef CONFIG_NO_HZ
- alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
+ zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
#endif
- alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+ zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
#endif /* SMP */

perf_event_init();
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