x86 Suspend/resume support in Hoary

[Matt Zimmerman]

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:
> 
> ----8<----
> Your kernel version doesn't match the kernel version that the 
> hibernation data was saved with, what would you like to do:
> 
> 1. Restart and try another kernel
> 2. Continue and loose the hibernation state
> 
> Choose [1]:
> ----8<----

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).

> >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.

-- 
 - mdz