lkml.org 
[lkml]   [2011]   [Dec]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 0/7] x86: BSP or CPU0 online/offline

* Ingo Molnar <mingo@elte.hu> wrote:

> Secondly, and more importantly, is there *any* hardware in
> existence that has a BIOS that can suspend/resume successfully
> with BSP offlined? If such hardware exists then we need to
> support it properly - initially perhaps by whitelisting such
> systems.

I suspect the answer to that is 'no' - as resume is really just
a fresh bootup of the physical CPU and BIOSen just start on the
boot CPU, no questions asked.

So the right approach there would be to detect the case where we
boot up back from S2RAM resume on an offlined CPU (the BSP is
really just one of the possibilities - in theory a S2RAM resume
could boot back up on any of the APs as well) - the resume code
should move off that CPU ASAP and keep that CPU offlined.

But the hibernation angle should be considered. Hibernation
already has to deal with the case where someone physically
unplugs a CPU and then resumes from the disk image, right? How
does the hibernation code handle that case currently?

Thanks,

Ingo


\
 
 \ /
  Last update: 2011-12-06 10:03    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site