[Intel-gfx] [PATCH 0/9] GPU-bound energy efficiency improvements for the intel_pstate driver.

[Chris Wilson]

I have to ask, if this is all just to work around iowait triggering high
frequencies for GPU bound applications, does it all just boil down to
i915 incorrectly using iowait. Does this patch set perform better than

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 9ca9c24b4421..7e7c95411bcd 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1267,7 +1267,7 @@ long i915_request_wait(struct i915_request *rq,
                        goto complete;
                }
 
-               timeout = io_schedule_timeout(timeout);
+               timeout = schedule_timeout(timeout);
        } while (1);
 
        GEM_BUG_ON(!intel_wait_has_seqno(&wait));

Quite clearly the general framework could prove useful in a broader
range of situations, but does the above suffice? (And can be backported
to stable.)
-Chris