Messages in this thread Patch in this message | | | Date | Fri, 16 Aug 2019 12:22:22 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: sched: Unexpected reschedule of offline CPU#2! |
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On Mon, 29 Jul 2019, Guenter Roeck wrote: > On Mon, Jul 29, 2019 at 12:47:45PM +0200, Peter Zijlstra wrote: > > On Mon, Jul 29, 2019 at 12:38:30PM +0200, Thomas Gleixner wrote: > > > Reboot has two modes: > > > > > > - Regular reboot initiated from user space > > > > > > - Panic reboot > > > > > > For the regular reboot we can make it go through proper hotplug, > > > > That seems sensible. > > > > > for the panic case not so much. > > > > It's panic, shit has already hit fan, one or two more pieces shouldn't > > something anybody cares about. > > > > Some more digging shows that this happens a lot with Google GCE intances, > typically after a panic. The problem with that, if I understand correctly, > is that it may prevent coredumps from being written. So, while of course > the panic is what needs to be fixed, it is still quite annoying, and it > would help if this can be fixed for panic handling as well. > > How about the patch suggested by Hillf Danton ? Would that help for the > panic case ?
I have no idea how that patch looks like, but the quick hack is below.
Thanks,
tglx
8<--------------- diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 75fea0d48c0e..625627b1457c 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -601,6 +601,7 @@ void stop_this_cpu(void *dummy) /* * Remove this CPU: */ + set_cpu_active(smp_processor_id(), false); set_cpu_online(smp_processor_id(), false); disable_local_APIC(); mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
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