Re: [RFC][PATCH] PM: Force GFP_NOIO during suspend/resume (was:Re: [linux-pm] Memory allocations in .suspend became very unreliable)

From: Maxim Levitsky
Date: Fri Jan 22 2010 - 05:11:21 EST


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.

Best regards,
Maxim Levitsky

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/