On 08/19/2014 04:38 AM, Don Zickus wrote: > On Mon, Aug 18, 2014 at 09:02:00PM +0200, Ingo Molnar wrote: >> >> * Don Zickus <dzickus@xxxxxxxxxx> wrote: >> >>>>>> So I agree with the motivation of this improvement, but >>>>>> is this implementation namespace-safe? >>>>> >>>>> What namespace are you worried about colliding with? I >>>>> thought softlockup_ would provide the safety?? Maybe I >>>>> am missing something obvious. :-( >>>> >>>> I meant PID namespaces - a PID in itself isn't guaranteed >>>> to be unique across the system. >>> >>> Ah, I don't think we thought about that. Is there a better >>> way to do this? Is there a domain id or something that can >>> be OR'd with the pid? >> >> What is always unique is the task pointer itself. We use pids >> when we interface with user-space - but we don't really do that >> here, right? > > No, I don't believe so. Ok, so saving 'current' and comparing that should > be enough, correct? > I am not sure of the safety about using pid here with namespace. But as to the pointer of process, is there a chance that we got a 'historical' address saved in the 'softlockup_warn_pid(or address)_saved' and the current hogging process happened to get the same task pointer address? If it never happens, I think the comparing of address is ok. thanks chai wen > Cheers, > Don > . > -- Regards Chai Wen -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
