Re: [igt-dev] [PATCH i-g-t 9/9] i915/gem_ctx_engine: Drip feed requests into 'independent'

Andi Shyti
2019-08-13T15:37:41Z

Hi Chris,

On Tue, Aug 13, 2019 at 07:20:16AM +0100, Chris Wilson wrote:
> The intent of the test is to exercise that each channel in the engine[]
> is an independent context/ring/timeline. It setups 64 channels pointing
> to rcs0 and then submits one request to each in turn waiting on a
> timeline that will force them to run out of submission order. They can
> only run in fence order and not submission order if the timelines of
> each channel are truly independent.
>
> However, we released the fences en masse, and once the requests are
> ready they are independent any may be executed in any order by the HW,

typo here

> especially true with timeslicing that may reorder the requests on a
> whim. So instead of releasing all requests at once, increment the
> timeline step by step and check we get our results advancing. If the
> requests can not be run in fence order and fall back to submission
> order, we will time out waiting for our incremental results and trigger
> a few GPU hangs.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110987
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Looks OK.

Reviewed-by: Andi Shyti <andi.shyti@intel.com>

Thanks,
Andi