Re: Hibernation Redesign

Nick Piggin
2007-07-09T04:39:55Z

Nick Piggin wrote:
> Jeremy Maitin-Shepard wrote:
>
>> Al Boldi <a1426z@gawab.com> writes:
>>
>>
>>> Pavel Machek wrote:
>>>
>>>> We are stuck with refrigerator for now, and at least for hibernation,
>>>> I don't see any feasible alternative.
>>
>>
>>
>>> Feasible alternative?
>>
>>
>>
>> I posted such an alternative to the list a short time ago: hibenrating
>> from a *new* kernel space/user space that is created by loading a new
>> kernel in a manner similar to what is done for kexec crashdumps. Unlike
>> kexec crashdumps, however, it would not require reserving any memory at
>> boot, because the necessary memory (maybe 16MB or 64MB) can be freed
>> just before hibernating, and device drivers can be properly stopped so
>> that DMAs don't stomp over certain memory.
>
>
> This is the Morton method, isn't it? :) I remember it sounding like a
> very good idea when he brought it up, but I can't remember the details
> of why it was rejected or what the problems were.

Hmm, and it seems like I won't get to know without reliving what
looks like an epic flamewar starting.... here:

http://thread.gmane.org/gmane.linux.kernel/374889

However from a quick look it seems like the only reason is the RAM
overhead of a reserve area. It seems unfortunate that it was
dismissed so quickly because of that problem (which could be
improved).

--
SUSE Labs, Novell Inc.