From: Chris Wilson Date: Tue, 24 Oct 2017 11:55:01 +0000 (+0100) Subject: drm/i915/execlists: Remove the priority "optimisation" X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=64b80085dd3603d401fc05879f700b86a3a5c8e8;p=linux.git drm/i915/execlists: Remove the priority "optimisation" Originally we set the priority to max upon inserting the request into the execlists queue (and removing it from the scheduler lists). We could then use the prio==INT_MAX as a shortcut within execlists_schedule() to detect the end of the dependency chain. Since commit 1f181225f8ec ("drm/i915/execlists: Keep request->priority for its lifetime") this is no longer true as we use the request completion as an indicator the schedule dependency chain is complete instead. (This allows us to then reschedule requests even when its context is in flight.) However, this makes the GEM_BUG_ON() inside execlists_schedule() racy as we may change the rq->prio at the same time. As the assertion is useful, let's keep the assertion and remove the micro-optimisation. Fixes: 1f181225f8ec ("drm/i915/execlists: Keep request->priority for its lifetime") Signed-off-by: Chris Wilson Cc: Michał Winiarski Cc: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20171024115501.21033-1-chris@chris-wilson.co.uk Reviewed-by: Michał Winiarski --- diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 5b87d5284a844..d36e256074354 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -734,7 +734,6 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine) list_for_each_entry_safe(rq, rn, &p->requests, priotree.link) { INIT_LIST_HEAD(&rq->priotree.link); - rq->priotree.priority = INT_MAX; dma_fence_set_error(&rq->fence, -EIO); __i915_gem_request_submit(rq); @@ -891,7 +890,6 @@ static void intel_lrc_irq_handler(unsigned long data) execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT); trace_i915_gem_request_out(rq); - rq->priotree.priority = INT_MAX; i915_gem_request_put(rq); execlists_port_complete(execlists, port);