On Tue, Jan 31, 2012 at 02:08:29PM -0800, Eric W. Biederman wrote: > > The problem is that although kdump tries to shutdown minimal hardware, > > it still needs to disable the IO APIC. This requires spinlocks which > > may be held by another cpu. This other cpu is being held infinitely in > > an NMI context by kdump in order to serialize the crashing path. Instant > > deadlock. > > Can you test to see if kexec on panic still needs to disable the IO > APIC. Last I looked we were close if not all of the way there to not > needing to boot the kernel in pic mode? Ok, so you just blindly remove disable_IO_APIC from native_machine_crash_shutdown and re-run some panic tests on various machines? What about the disable_IO_APIC path in native_machine_shutdown? Also, where could I look to see if that work was done? Is that in the ioapic setup code? > > If we can skip the ioapic disable entirely we should be much more > robust. Agreed. Cheers, Don
