> Date: Sat, 15 Oct 2016 09:55:05 +0200 (CEST) > From: s...@openbsd.org > > On Fri, 14 Oct 2016, Mike Larkin wrote: > > > On Fri, Oct 14, 2016 at 04:49:31PM +0900, YASUOKA Masahiko wrote: > > > Hi, > > > > > > I'm working on NEC Express5800/R110h-1 (dmesg is attached). On this > > > machine, our kernel panics with following message. > > > > > > cpu0 at mainbus0panic: cpu at apic id 0 already attached? > > > > > > This seems to happen since x2APIC on the machine is enabled by BIOS > > > and the kernel doesn't assume that. The diff makes the kernel use > > > x2APIC if it is enabled by BIOS. > > > > > > ok? > > > > > > > This should go in snaps, or wait for reports from tech@ with test results > > before it should be committed, IMO. We don't have full support for x2apic, > > and blindly enabling it like this hoping that the bios set everything up > > right is bound to be a bad assumption on at least one machine out there. > > As I understand the code, it should only change behavior on systems where > x2apic is enabled by the bios. And currently on such systems openbsd will > not work anyway, because we then try to use xapic mode without disabling > x2apic mode. Or am I missing something?
No, I think you're right and the risk of the diff is low.
