[Intel-gfx] [PATCH] drm/i915: Add aub debug support for kernel

[Liu Aleaxander]

On Sat, Nov 6, 2010 at 1:11 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> Right. If we want to ask the user to gather some debug info, it
> essentially has to be from within X and be as simple as run
> 'intel-gpu-trace myapp'.

Some notes here: let's me try to make it clear this time. As I had
said, we can easily get an aub file at user space for Mesa and the
media part by:
$ export INTEL_DEBUG=aub
$ run-you-app-here.

Then an aub file is generated(i965.aub for mesa). This work is done at
libdrm, and for now, it works pretty well. While, for some reason, we
didn't release it out, but it should be soon;)

While, what we can't do at user space is to get the KMS data to make
an aub file. And this is what the patch for.

So, on the whole. We use libdrm to get an aub file, which collects the
batchbuffer and all the auxiliary buffers, at user space. While, this
patch to get an aub file for the KMS phase.

>Using ftrace is the simplest way to achieve that.

Then I got your idea;)  I will check this tomorrow.

Thanks!

>Having to rmmod i915.ko rules out mmiotrace as a viable candidate.
> But we can easy add two tracepoints to I915_READ and I915_WRITE which can
> be enabled at runtime, exported via /sys/kernel/debug/tracing and
> automated in a little tool.
> -Chris
>
> --
> Chris Wilson, Intel Open Source Technology Centre
>



-- 
regards
Yuanhan Liu