Re: Linux 5.3-rc7

[Chris Wilson]

Quoting Linus Torvalds (2019-09-02 18:28:26)
> Bandan Das:
>       x86/apic: Include the LDR when clearing out APIC registers

Apologies if this is known already, I'm way behind on email.

I've bisected

[   18.693846] smpboot: CPU 0 is now offline
[   19.707737] smpboot: Booting Node 0 Processor 0 APIC 0x0
[   29.707602] smpboot: do_boot_cpu failed(-1) to wakeup CPU#0

https://intel-gfx-ci.01.org/tree/drm-tip/igt@perf_pmu@cpu-hotplug.html

to 558682b52919. (Reverts cleanly and fixes the problem.)

I'm guessing that this is also behind the suspend failures, missing
/dev/cpu/0/msr, and random perf_event_open() failures we have observed
in our CI since -rc7 across all generations of Intel cpus.
-Chris