Re: [RFC PATCH v1 2/3] PM / Runtime: force memory allocation with no I/O during runtime_resume callbcack

From: Rafael J. Wysocki
Date: Thu Oct 18 2012 - 19:13:05 EST


On Wednesday 17 of October 2012 19:07:25 Ming Lei wrote:
> On Wed, Oct 17, 2012 at 1:43 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> >
> > This appears to be a bit too heavy handed. First of all, it seems to affect
> > all memory allocations going in parallel with the resume callback. Second,
>
> No, the flag is per task, only memory allocation inside resume callback
> is effected.

OK

> > it affects all resume callbacks, not only those where the problem really
>
> We can do it only on block device, block device's ancestor and network
> devices(iSCSI case), but that may introduce policy into PM core or add
> one flag of memalloc_noio_resume into 'dev_pm_info', could you agree
> on it?

Well, the question is how many runtime resume callbacks actually allocate
memory. If they are not too many, we can just flag all of them. Otherwise,
adding a flag may be a better approach. I'm not sure ATM.

Thanks,
Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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