Re: [patch 0/2] suspend/resume regression fixes

[Bill Davidsen <davidsen@tmr.com>]

Mark Lord wrote:
> Linus Torvalds wrote:
>>
>> On Sat, 22 Sep 2007, Thomas Gleixner wrote:
>>> My final enlightment was, when I removed the ACPI processor module,
>>> which controls the lower idle C-states, right before resume; this
>>> worked fine all the time even without all the workaround hacks.
>>>
>>> I really hope that this two patches finally set an end to the "jinxed
>>> VAIO heisenbug series", which started when we removed the periodic
>>> tick with the clockevents/dyntick patches.
>>
>> Ok, so the patches look fine, but I somehow have this slight feeling 
>> that you gave up a bit too soon on the "*why* does this happen?" 
>> question.
> 
> On a closely related note:  I just now submitted a patch to fix 
> SMP-poweroff,
> by having it do disable_nonboot_cpus before doing poweroff.
> 
> Which has led me to thinking..
> ..are similar precautions perhaps necessary for *all* ACPI BIOS calls?
> 
> Because one never knows what the other CPUs are doing at the same time,
> and what the side effects may be on the ACPI BIOS functions.
> 
> And also, I wonder if at a minimum we should be guaranteeing ACPI BIOS 
> calls
> only ever happen from CPU#0 (or the "boot" CPU)?   Or do we do that 
> already?
> 
Boot CPU, and AFAIK suspend is the only place which does it.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot