Messages in this thread | | | Date | Tue, 8 Dec 2015 05:09:03 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 1/4] cpumask: Migrate 'alloc_cpumask_var()' users to 'zalloc_cpumask_var()' |
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* Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Mon, Dec 7, 2015 at 12:49 AM, Ingo Molnar <mingo@kernel.org> wrote: > > Xunlei Pang reported a scheduler bug in init_rootdomain(), which is > > caused by improper use of alloc_cpumask_var(), which results in > > uninitialized cpumasks being allocated. > > > > No-one noticed this scheduler bug for a long time, probably because > > alloc_cpumask_var() does result in initialized cpumasks in the > > !CPUMASK_OFFSTACK case - which is the vast majority of systems > > out there. > > > > So migrate all alloc_cpumask_var() users over to zalloc_cpumask_var(), to be > > on the safe side. > > Ugh. I'd rather just see us say that "allocating a cpumask always returns a > zeroed mask". > > There really is no reason to ever not zero it (they aren't _that_ big even on > huge machines), so I'd rather just get rid of the "zalloc" version that is the > less common one anyway.
Sure - that was my original suggestion, will reshape the series to do it like that.
Thanks,
Ingo
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