Re: [RFC 03/11] drm/i915: Add reset stats entry point for per-engine reset.

Daniel Vetter
2015-06-16T13:45:25Z

On Mon, Jun 08, 2015 at 06:33:59PM +0100, Chris Wilson wrote:
> On Mon, Jun 08, 2015 at 06:03:21PM +0100, Tomas Elf wrote:
> > In preparation for per-engine reset add way for setting context reset stats.
> >
> > OPEN QUESTIONS:
> > 1. How do we deal with get_reset_stats and the GL robustness interface when
> > introducing per-engine resets?
> >
> > a. Do we set context that cause per-engine resets as guilty? If so, how
> > does this affect context banning?
>
> Yes. If the reset works quicker, then we can set a higher threshold for
> DoS detection, but we still do need Dos detection?
>
> > b. Do we extend the publically available reset stats to also contain
> > per-engine reset statistics? If so, would this break the ABI?
>
> No. The get_reset_stats is targetted at the GL API and describing it in
> terms of whether my context is guilty or has been affected. That is
> orthogonal to whether the reset was on a single ring or the entire GPU -
> the question is how broad do want the "affected" to be. Ideally a
> per-context reset wouldn't necessarily impact others, except for the
> surfaces shared between them...

gl computes sharing sets itself, the kernel only tells it whether a given
context has been victimized, i.e. one of it's batches was not properly
executed due to reset after a hang.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation