Re: [PATCH v4 06/38] drm/i915: Re-instate request->uniq because it is extremely useful

Chris Wilson
2016-01-11T22:04:15Z

On Mon, Jan 11, 2016 at 06:42:35PM +0000, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
>
> The seqno value cannot always be used when debugging issues via trace
> points. This is because it can be reset back to start, especially
> during TDR type tests. Also, when the scheduler arrives the seqno is
> only valid while a given request is executing on the hardware. While
> the request is simply queued waiting for submission, it's seqno value
> will be zero (meaning invalid).

Even with per-context seqno that can be assigned before execution as we
know that requests within a context cannot be reordered?
-Chris

--
Chris Wilson, Intel Open Source Technology Centre