Messages in this thread |  | | Date | Fri, 10 Feb 2012 10:42:55 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH] xen/cpu: Make VCPU hotplug code online CPUs properly. |
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On Fri, Feb 10, 2012 at 03:03:46PM +0000, Ian Campbell wrote: > On Fri, 2012-02-10 at 14:43 +0000, Konrad Rzeszutek Wilk wrote: > > Offlining CPUs works. Onlining does not work anymore and it looks > > like we were missing a cpu_up() call in the hotplug bring up path. > > Wasn't this a deliberate decision as part of the pvops upstreaming to be > consistent with native cpu hotplug? After hotplugging a CPU
Ah, hadn't seen that. Thanks for spotting that!
> administrator action is needed to actually online it. > > http://xen.1045712.n5.nabble.com/cpu-down-but-no-cpu-up-in-drivers-xen-cpu-hotplug-c-td2545244.html > > The fix is to add a udev rule: > http://wiki.xen.org/wiki/Paravirt_Linux_CPU_Hotplug
Ah, so I see that it is run (the udev does it) but it actually does not bring the CPU up.
It looks as if the 'online' attribute is actually not present at all, even after bringing the CPU "up-but-not-online". Oh joy! Should be easy to reproduce on baremetal.
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