Messages in this thread | | | Date | Mon, 9 Apr 2007 14:03:52 +0000 | From | Pavel Machek <> | Subject | Re: [RFD] CPU hotplug and suspend |
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Hi!
> Currently, we use the CPU hotplug to disable nonboot CPUs in the suspend code > paths, but with the recent change of code ordering (ie. nonboot CPUs are > disabled after freezing tasks _and_ devices) it has become quite troublesome. > The reason of this is that there are some CPU hotplug notifiers registered and > called on each run of cpu_up()/cpu_down() that assume the system to be fully > functional, which is not the case during the suspend. Moreover, at least some > of them do things that are not really necessary for disabling or enabling the > nonboot CPUs.
Right.
> The advantage of using the CPU hotplug (in its current form) for suspending is > that if some CPUs don't reappear during the resume, we are safe. Still, I > think it would be more appropriate, and simpler in the long run, to notify the > interested subsystems _only_ if one (or more) CPUs are not functional after the > resume.
I'm afraid that adding 'cpu not there so simulate unplug' path will make it complex, and prone to failure, as _noone_ is going to test it.
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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