Commit bdddd296 authored Dec 02, 2009 by Rusty Russell Committed by Ingo Molnar Dec 02, 2009

sched: Fix isolcpus boot option



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.

I introduced this regression in 49557e62 (sched: Fix
boot crash by zalloc()ing most of the cpu masks).

Use the bootmem allocator if they set isolcpus=, otherwise
allocate and zero like normal.

Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: peterz@infradead.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <200912021409.17013.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Anton Blanchard <anton@samba.org>

parent 8592e648

kernel/sched.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -8061,6 +8061,7 @@ 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;
		}
		@@ -9609,6 +9610,8 @@ void __init sched_init(void)
		zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
		alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
		#endif
		/* May be allocated at isolcpus cmdline parse time */
		if (cpu_isolated_map == NULL)
		zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
		#endif /* SMP */

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