Re: [ACPI] Re: S4bios support for 2.5.63

[Roger Luethi <rl@hellgate.ch>]

On Tue, 04 Mar 2003 11:06:50 +1300, Nigel Cunningham wrote:
> On Tue, 2003-03-04 at 03:30, Roger Luethi wrote:
> > Not sure I follow all of your story but I can confirm that hdparm -u1
> > successfully gets me to the kernel panic due to highmem support still
> > lacking -- i.e. way beyond the BUG_ON() I've been hitting. So it looks
> > like you found a good work-around.
> 
> You were hitting the BUG_ON before swsusp was even trying to write the
> image?!! That is interesting! Since count_and_copy is first called post
> driver suspend in the current version, perhaps they are somehow related.
> (This is before swsusp tries to write any of the image to disk).

Huh? After a glance at the code I agree that drivers_suspend happens before
count_and_copy_data_pages, but that means hitting the BUG_ON in
idedisk_suspend before the panic in count_and_copy_data_pages is what I'd
expect. How is that remarkable? ... My current kernel has HIGHMEM enabled,
but previous ones that failed the same way didn't.

Anyway, a few more tests showed that hdparm -u1 helps if I have lots of
memory used (say for fs caches). In two out of two tests, I saw Pavel's
request to send him 1 GB RAM via email.

Suspending directly from a clean boot (after issuing the same hdparm -u1
commands for both disks) I hit the BUG_ON in idedisk_suspend (two out of
two tests, too).

Roger