Messages in this thread | | | Date | Thu, 8 Jan 2009 10:30:52 -0500 (EST) | From | Steven Rostedt <> | Subject | Re: [PATCH -v7][RFC]: mutex: implement adaptive spinning |
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On Thu, 8 Jan 2009, Steven Rostedt wrote: > > > > + /* > > > > + * We need to validate that we can do a > > > > + * get_cpu() and that we have the percpu area. > > > > + */ > > > > + if (!cpu_online(cpu)) > > > > + goto out; > > > > > > Should we need to do a "get_cpu" or something? Couldn't the CPU disappear > > > between these two calls. Or does it do a stop-machine and the preempt > > > disable will protect us? > > > > Did you miss the preempt_disable() a bit up? > > No, let me rephrase it better. Does the preempt_disable protect against > another CPU from going off line? Does taking a CPU off line do a > stop_machine?
I just looked at the cpu hotplug code, and it does call stop machine. All is in order ;-)
-- Steve
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