Re: [Update][PATCH] MM / PM: Force GFP_NOIO during suspend/hibernation and resume

Maxim Levitsky
2010-01-23T09:29:28Z

On Fri, 2010-01-22 at 22:19 +0100, Rafael J. Wysocki wrote:
> On Friday 22 January 2010, Maxim Levitsky wrote:
> > On Fri, 2010-01-22 at 10:42 +0900, KOSAKI Motohiro wrote:
> > > > > > Probably we have multiple option. but I don't think GFP_NOIO is good
> > > > > > option. It assume the system have lots non-dirty cache memory and it isn't
> > > > > > guranteed.
> > > > >
> > > > > Basically nothing is guaranteed in this case. However, does it actually make
> > > > > things _worse_?
> > > >
> > > > Hmm..
> > > > Do you mean we don't need to prevent accidental suspend failure?
> > > > Perhaps, I did misunderstand your intention. If you think your patch solve
> > > > this this issue, I still disagree. but If you think your patch mitigate
> > > > the pain of this issue, I agree it. I don't have any reason to oppose your
> > > > first patch.
> > >
> > > One question. Have anyone tested Rafael's $subject patch?
> > > Please post test result. if the issue disapper by the patch, we can
> > > suppose the slowness is caused by i/o layer.
> >
> > I did.
> >
> > As far as I could see, patch does solve the problem I described.
> >
> > Does it affect speed of suspend? I can't say for sure. It seems to be
> > the same.
>
> Thanks for testing.

I'll test that too, soon.
Just to note that I left my hibernate loop run overnight, and now I am
posting from my notebook after it did 590 hibernate cycles.

Offtopic, but Note that to achieve that I had to stop using global acpi
hardware lock. I tried all kinds of things, but for now it just hands
from time to time.
See http://bugzilla.kernel.org/show_bug.cgi?id=14668

Best regards,
Maxim Levitsky