Messages in this thread | | | Date | Mon, 26 Dec 2016 22:16:26 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [GIT pull] smp/hotplug: Removal of notifiers |
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On Mon, 26 Dec 2016, Borislav Petkov wrote: > On Mon, Dec 26, 2016 at 07:21:44PM +0100, Thomas Gleixner wrote: > > Is there anything interesting error message before the BUG hits? I'll try > > to reproduce on a AMD box tomorrow. > > Hmm, so lemme see if I see it correctly: > > threshold_create_bank() does kobject_create_and_add(name, &dev->kobj); > and that dev thing is > > struct device *dev = per_cpu(mce_device, cpu); > > BUT(!), those mce_device per-CPU things get initialized in > > mce_cpu_online() > |-> mce_device_create(cpu); > > With a CONFIG_HOTPLUG_CPU=n .config that doesn't happen, right? > > Oh, and I see what could've changed that: > > 8c0eeac819c8 ("x86/mcheck: Move CPU_ONLINE and CPU_DOWN_PREPARE to hotplug state machine") > > And before that, we did call mce_device_create(cpu) in > mcheck_init_device() which is a device initcall and not dependent on CPU > hotplug. > > And frankly, flipping back to the for_each_online_cpu(i) is yucky as > hell but I don't see any other/better solution besides pulling up > mce_device_create() into mcheck_init_device()...
The hotplug callbacks are invoked even with HOTPLUG=n. So that's not the problem. I can reproduce it. Will post info once I understand it.
Thanks,
tglx
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