drm/i915/gt: Delay release of engine-pm after last retirement (edee52c9) · Commits · 戴 / test

Keep the engine-pm awake until the next jiffie, to avoid immediate ping-pong under moderate load. (Forcing the idle barrier excerbates the moderate load, dramatically increasing the driver overhead.) On the other hand, delaying the idle-barrier slightly incurs longer rc6-off and so more power consumption. Closes: https://gitlab.freedesktop.org/drm/intel/issues/848 Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200323092841.22240-4-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_context.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -350,7 +350,7 @@ void intel_context_enter_engine(struct intel_context *ce)
		void intel_context_exit_engine(struct intel_context *ce)
		{
		intel_timeline_exit(ce->timeline);
		intel_engine_pm_put(ce->engine);
		intel_engine_pm_put_delay(ce->engine, 1);
		}

		int intel_context_prepare_remote_request(struct intel_context *ce,

drivers/gpu/drm/i915/i915_active.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -818,7 +818,7 @@ void i915_active_acquire_barrier(struct i915_active *ref)

		GEM_BUG_ON(!intel_engine_pm_is_awake(engine));
		llist_add(barrier_to_ll(node), &engine->barrier_tasks);
		intel_engine_pm_put(engine);
		intel_engine_pm_put_delay(engine, 1);
		}
		}

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