[Intel-gfx] [RFC] Tracing infrastructure for driver performance

[Chris Wilson]

This is the tip of a series of patches I've pushed to
http://cgit.freedesktop.org/~ickle/linux-2.6 in the i915/perf branch. It
is the most interesting as it has the most potential for us to write
tools with which to analyse performance.

It uses the tracepoints+ftrace to conditionally relay state about
buffers (creation, domain change, bind/unbind, etc) and requests
(batch submission, flushes, completion, waits etc)) to user space. This
captures the information tagged with WATCH_BUF and WATCH_EXEC and I think
is sufficient to be able to monitor concurrency between the CPU and GPU.

I'd appreciate review and suggestions.
-ickle