Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | Re: [PATCH] sched: Fix isolcpus boot option | Date | Tue, 1 Dec 2009 11:14:09 +1030 |
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On Mon, 30 Nov 2009 10:35:32 am Anton Blanchard wrote: > > We allocate and zero cpu_isolated_map after the isolcpus __setup option > has run. This means cpu_isolated_map always ends up empty and if > CPUMASK_OFFSTACK is enabled we write to a cpumask that hasn't been > allocated. > > To keep the fix to a minimum this patch stores a pointer to the cmdline > option and parses it after we allocate and zero the cpumask.
I introduced this regression in:
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
But this change made isolcpus= never work, CPUMASK_OFFSTACK or no.
Your patch works and is minimal.
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Thanks, Rusty.
PS. This would have also worked:
diff --git a/kernel/sched.c b/kernel/sched.c --- a/kernel/sched.c +++ b/kernel/sched.c @@ -8045,6 +8045,7 @@ static cpumask_var_t cpu_isolated_map; /* Setup the mask of cpus configured for isolated domains */ static int __init isolated_cpu_setup(char *str) { + alloc_bootmem_cpumask_var(&cpu_isolated_map); cpulist_parse(str, cpu_isolated_map); return 1; } @@ -9571,7 +9572,9 @@ void __init sched_init(void) zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); #endif - zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); + /* May be allocated at isolcpus cmdline parse time */ + if (cpu_isolated_map == NULL) + zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); #endif /* SMP */ perf_event_init();
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