From: Chris Wilson Date: Tue, 15 Oct 2019 13:26:06 +0000 (+0100) Subject: drm/i915: Flush tasklet submission before sleeping on i915_request_wait X-Git-Tag: v5.5-rc1~128^2~30^2~72 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=193065024072c0d6f2972142d5df5a00b33324c6;p=linux.git drm/i915: Flush tasklet submission before sleeping on i915_request_wait If the system is being slow and userspace is racing ahead of the GPU and finds itself waiting for the GPU to catch up, before the process sleeps give the tasklet a kick, bypassing ksoftirqd. If the system is overloaded, then ksoftirqd may be delayed incurring additional latency to our user. This should not be a frequent problem, but in the past we have observed several hundred millisecond delays before ksoftirqd services an interrupt, so burn a few cycles to lend a helping hand. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191015132606.14349-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index b8a54572a4f8..f1cadad4e81c 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1496,6 +1496,7 @@ long i915_request_wait(struct i915_request *rq, break; } + intel_engine_flush_submission(rq->engine); timeout = io_schedule_timeout(timeout); } __set_current_state(TASK_RUNNING);