Re: [PATCH v2 00/25] AMDKFD kernel driver

From: Daniel Vetter
Date: Tue Jul 22 2014 - 07:15:23 EST


On Tue, Jul 22, 2014 at 12:52:43PM +0300, Oded Gabbay wrote:
> On 22/07/14 12:21, Daniel Vetter wrote:
> >On Tue, Jul 22, 2014 at 10:19 AM, Oded Gabbay <oded.gabbay@xxxxxxx> wrote:
> >>>Exactly, just prevent userspace from submitting more. And if you have
> >>>misbehaving userspace that submits too much, reset the gpu and tell it
> >>>that you're sorry but won't schedule any more work.
> >>
> >>I'm not sure how you intend to know if a userspace misbehaves or not. Can
> >>you elaborate ?
> >
> >Well that's mostly policy, currently in i915 we only have a check for
> >hangs, and if userspace hangs a bit too often then we stop it. I guess
> >you can do that with the queue unmapping you've describe in reply to
> >Jerome's mail.
> >-Daniel
> >
> What do you mean by hang ? Like the tdr mechanism in Windows (checks if a
> gpu job takes more than 2 seconds, I think, and if so, terminates the job).

Essentially yes. But we also have some hw features to kill jobs quicker,
e.g. for media workloads.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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