[Intel-gfx] [PATCH] drm/i915: Do not use iowait while waiting for the GPU

[Chris Wilson]

A recent trend for cpufreq is to boost the CPU frequencies for
iowaiters, in particularly to benefit high frequency I/O. We do the same
and boost the GPU clocks to try and minimise time spent waiting for the
GPU. However, as the igfx and CPU share the same TDP, boosting the CPU
frequency will result in the GPU being throttled and its frequency being
reduced. Thus declaring iowait negatively impacts on GPU throughput.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107410
References: 52ccc4314293 ("cpufreq: intel_pstate: HWP boost performance on IO wakeup")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Eero Tamminen <eero.t.tamminen at intel.com>
Cc: Francisco Jerez <currojerez at riseup.net>
---
 drivers/gpu/drm/i915/i915_request.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 5c2c93cbab12..7ef7ade12073 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1330,7 +1330,7 @@ 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));
-- 
2.18.0