Re: does hibernate to disk try hard enough to free memory?

From: Martin Steigerwald
Date: Wed Feb 23 2011 - 09:11:22 EST


Am Tuesday 22 February 2011 schrieb Rafael J. Wysocki:
> On Tuesday, February 22, 2011, Martin Steigerwald wrote:
> > Am Tuesday 22 February 2011 schrieb Rafael J. Wysocki:
> > > On Tuesday, February 22, 2011, Martin Steigerwald wrote:
> > > > Hi!
> > > >
> > > > Since Radeon KMS I often have it that my ThinkPad T42 with 2 MiB
> > > > of RAM is not able to allocate memory for the hibernation image.
> > > > Before KMS hibernation only very rarely failed for that reason.
> > > >
> > > > Often I run without compositing at all as I believe this might
> > > > spare some pages as well. But this doesn't always help.
> > > >
> > > > It complains that to less pages could be freed. For example with
> > > > kernel 2.6.37:
> > > >
> > > > Feb 16 00:15:00 shambhala kernel: PM: Creating hibernation image:
> > > > Feb 16 00:15:00 shambhala kernel: PM: Need to copy 186577 pages
> > > > Feb 16 00:15:00 shambhala kernel: PM: Normal pages needed: 114411
> > > > + 1024, available pages: 112767
> > > > Feb 16 00:15:00 shambhala kernel: PM: Not enough free memory
> > > > Feb 16 00:15:00 shambhala kernel: PM: Error -12 creating
> > > > hibernation image Feb 16 00:15:00 shambhala kernel: Extended
> > > > CMOS year: 2000 Feb 16 00:15:00 shambhala kernel: ACPI: Waking
> > > > up from system sleep state S4
> > > > Feb 16 00:15:00 shambhala kernel: PM: early recover of devices
> > > > complete after 0.376 msecs
> > >
> > > What's the value in /sys/power/image_size?
> >
> > shambhala:~> cat /sys/power/image_size
> > 844206080
> >
> > Should I try with less?
>
> Yes, please. Try with 700000000 for example.

I replaced dropping by settings image_size to this valua and the ThinkPad
hibernated with KMail open. Thus seems to work, but I will test a bit
further.

Where does the higher value previously set come from? Autotuning? Is there
anything that can be improved with autotuning? If yes, I can file a bug
report. Otherwise I just try to find a good value for image size and be
done with it.

Thanks,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7

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