[igt-dev] [Intel-gfx] [PATCH i-g-t 1/1] igt_aux: Skip hibernation attempts if hibernation is not configured

[Petri Latvala]

On Thu, Dec 21, 2017 at 12:59:41PM +0000, Chris Wilson wrote:
> Quoting Petri Latvala (2017-12-21 12:53:41)
> > rtcwake doesn't give us meaningful ways of differentiating different
> > reasons for hibernation failing. CI doesn't configure hibernation to
> > work at this time, and hibernation attempts will always fail. Check
> > for the configuration in the form of resume= appearing on the kernel
> > command line, which is what swsusp uses to find the resume device to
> > hibernate to.
> 
> resume= is not required for hibernation.

Oh bugger, I was blind. swsusp_resume_device update is right there in
swsusp_swap_check().

swsusp_resume_block is not updated there though. That's needed to
hibernate to swapfile.

>  
> > Hibernation failures have dug up a couple of bugs in the past, but
> > finding actual bugs in the swamp of "rtcwake failed with 1" results is
> > difficult enough to overweigh that benefit.
> 
> The ones in CI are genuine though, does it not appear? At the start of
> the hibernate it picks swapspace to store the image, but at the end of
> the sequence, it can not read back from the swapspace it chose.

... and the above is what happens in CI. Correct device is checked but
offset is missing.

Suggestions how to proceed? Does resuming from a swapfile work
automatically without resume_offset= on cmdline? Then it would be a
matter of updating swsusp_resume_block in swsusp_swap_check. If not,
check that either 1) a partition exists in /proc/swaps 2)
resume_offset is on cmdline?



-- 
Petri Latvala