Re: [linux-pm] Proposal for a new algorithm for reading & writing a hibernation image.

[Nigel Cunningham <ncunningham@crca.org.au>]

Hi.

On 30/05/10 15:25, Pavel Machek wrote:
> Hi!
>
>> 2. Prior to writing any of the image, also set up new 4k page tables
>> such that an attempt to make a change to any of the pages we're about to
>> write to disk will result in a page fault, giving us an opportunity to
>> flag the page as needing an atomic copy later. Once this is done, write
>> protection for the page can be disabled and the write that caused the
>> fault allowed to proceed.
>
> Tricky.
>
> page faulting code touches memory, too...

Yeah. I realise we'd need to make the pages that are used to record the 
faults be unprotected themselves. I'm imagining a bitmap for that.

Do you see any reason that it could be inherently impossible? That's 
what I really want to know before (potentially) wasting time trying it.

Regards,

Nigel