[Intel-gfx] [PATCH 2/2] drm/i915/tracepoints: Remove DRM_I915_LOW_LEVEL_TRACEPOINTS Kconfig option

[Joonas Lahtinen]

Quoting Tvrtko Ursulin (2018-08-08 15:56:01)
> On 08/08/2018 13:42, Chris Wilson wrote:
> > Quoting Tvrtko Ursulin (2018-08-08 13:13:08)
> This is true, no disagreement. My point simply was that we can provide 
> this info easily to anyone. There is a little bit of analogy with perf 
> scheduler tracing/map etc.
> 
> > I don't see any value in giving the information away, just the cost. If
> > you can convince Joonas of its merit, and if we can define just exactly
> > what ABI it constitutes, then I'd be happy to be the one who says "I
> > told you so" in the future for a change.
> 
> I think Joonas was okay in principle that we soft-commit to _trying_ to 
> keep _some_ tracepoint stable-ish (where it makes sense and after some 
> discussion for each) if IGT also materializes which auto-pings us (via 
> CI) when we break one of them. But I may be misremembering so Joonas 
> please comment.

Currently gpuvis, using these, seems to be only packaged in one AUR repo,
and they do make a not in the wiki how you need to configure kernel for
debugging. And there's been no apparent demand for them to have it in
stock kernel.

And even when we do get demand for having gpuvis or another tool working
from vanilla kernel, tracepoints being a rather tricky subject, I would
start the discussion by going through alternative means of providing the
information the tool needs and considering those.

So lets still keep this option as it was introduced. The whole
"tracepoints as stable uAPI" idea is a can of worms which is only dug
into when other options are exhausted.

Regards, Joonas