When called from process context tasklet_schedule() defers itself to ksoftirqd. From experience this may cause unacceptable latencies of over 200ms in executing the submission tasklet, our goal is to reprioritise the HW execution queue and trigger preemption immediately, so convert the rcu protection over to include a kick of the tasklet. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_gem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5ece6ae4bdff..03cd30001b5d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -578,10 +578,10 @@ static void __fence_set_priority(struct dma_fence *fence, rq = to_request(fence); engine = rq->engine; - rcu_read_lock(); + local_bh_disable(); /* RCU serialisation for set-wedged protection */ if (engine->schedule) engine->schedule(rq, attr); - rcu_read_unlock(); + local_bh_enable(); /* kick the tasklets if queues were reprioritised */ } static void fence_set_priority(struct dma_fence *fence, -- 2.17.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
