The following commit has been merged in the linux branch: commit 49557e620339cb134127b5bfbcfecc06b77d0232 Author: Rusty Russell rusty@rustcorp.com.au Date: Mon Nov 2 20:37:20 2009 +1030

sched: Fix boot crash by zalloc()ing most of the cpu masks

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@rustcorp.com.au Cc: Peter Zijlstra peterz@infradead.org LKML-Reference: 200911022037.21282.rusty@rustcorp.com.au Signed-off-by: Ingo Molnar mingo@elte.hu

diff --git a/kernel/sched.c b/kernel/sched.c index cae6700..bf21adb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9535,13 +9535,13 @@ 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();