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Date: Sun, 28 Feb 2016 15:49:33 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
cc: LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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Subject: Re: [patch 10/20] cpu/hotplug: Make target state writeable
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Rafael,

On Sat, 27 Feb 2016, Rafael J. Wysocki wrote:
> Say we've taken all of them offline and now we are ready to eject.  If an
> online from sysfs (or any other place) comes in at this point, we'll be
> ejecting a CPU that's potentially doing something which is not awesome.
> 
> That's why we have device_hotplug_lock and some ugly code related to it.
> 
> It extends to parents and children somewhat because of device objects
> representing packages (we want those to be "offline" only if all their
> children are offline) and that's why the lock is held around offline from
> sysfs too.
> 
> I'm not entirely happy with this for quite obvious reasons, but it gets
> the job done ATM.

Understood. I'll fix that thing up so that won't happen and I put it on the
list of things to look at deeper.

Thanks,

	tglx