Messages in this thread |  | | | Date | Mon, 16 Aug 2010 10:12:50 -0400 | | From | Don Zickus <> | | Subject | Re: fix BUG: using smp_processor_id() in touch_nmi_watchdog and touch_softlockup_watchdog |
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On Mon, Aug 16, 2010 at 03:46:58PM +0200, Peter Zijlstra wrote: > > I don't see a problem with the patch, but my low level understanding of > > the __get_cpu_var vs. per_cpu isn't very strong. > > __get_cpu_var() gets you the value on the current cpu, per_cpu() takes a > cpu argument.
Well I know that much. :-) It seems that __get_cpu_var depends on preemption being disabled whereas per_cpu does not? Though for some reason I thought __get_cpu_var would be more atomic when it grabbed the current cpu such that you wouldn't need to disable preemption. Guess not.
Cheers, Don
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