x86 Suspend/resume support in Hoary

[Sami Haahtinen]

Matt Zimmerman wrote:
> On Sat, Feb 05, 2005 at 12:28:17PM +0200, Sami Haahtinen wrote:
>>>- If the resume fails due to a mismatch, halt, giving the user a chance to
>>> recover
>>
>>This could be a big disaster too. if the user doesn't have anything but 
>>a single kernel, how would one recover? Somekind of menu might be a good 
>>idea:
> 
> This should be a very rare case, if we can correctly prevent hibernation
> when we can predict that the next boot would be a mismatch.  I don't think
> we need to optimize for it, but we should add a safety feature to prevent
> this from inadvertently happening (the kernel command line should need to be
> changed explicitly in order to cause this behaviour).

The reason why i brought it up was if we assume that a normal user can 
deal with the situation (even though it should be rare) then the 
instructions should be even more clear when things do go wrong.

>>>Would it help to sync() just before going to sleep, to reduce the risk of
>>>corruption if anything goes wrong with the resume?
>>
>>Unless you can tell all of the user apps to do a save and then sync, 
>>this would help. Other than that, it's pretty much the same as turning 
>>off your computer unwarned.
> 
> The difference between unsaved data in applications, and possibly severe
> filesystem corruption, is enough to justify a small effort I think.

Ah, if we are trying to deal with filesystem corruption, simple sync 
would be enough. Although, i'm not too familiar with the way kernel 
deals with filesystems, but i would assume sync() before spinning down 
the disks should be enough.

And syncing should be a sane thing to do anyway...

- S