From ac1a6d7310e238b4781708283d441625c8e7da25 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 24 Dec 2020 13:55:43 +0000 Subject: [PATCH] drm/i915/gt: Simplify virtual engine handling for execlists_hold() Now that the tasklet completely controls scheduling of the requests, and we postpone scheduling out the old requests, we can keep a hanging virtual request bound to the engine on which it hung, and remove it from te queue. On release, it will be returned to the same engine and remain in its queue until it is scheduled; after which point it will become eligible for transfer to a sibling. Instead, we could opt to resubmit the request along the virtual engine on unhold, making it eligible for load balancing immediately -- but that seems like a pointless optimisation for a hanging context. Signed-off-by: Chris Wilson Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20201224135544.1713-8-chris@chris-wilson.co.uk --- .../gpu/drm/i915/gt/intel_execlists_submission.c | 29 ---------------------- 1 file changed, 29 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index 2d7a1440c31a..dc1312d862ed 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -2048,35 +2048,6 @@ static bool execlists_hold(struct intel_engine_cs *engine, goto unlock; } - if (rq->engine != engine) { /* preempted virtual engine */ - struct virtual_engine *ve = to_virtual_engine(rq->engine); - - /* - * intel_context_inflight() is only protected by virtue - * of process_csb() being called only by the tasklet (or - * directly from inside reset while the tasklet is suspended). - * Assert that neither of those are allowed to run while we - * poke at the request queues. - */ - GEM_BUG_ON(!reset_in_progress(&engine->execlists)); - - /* - * An unsubmitted request along a virtual engine will - * remain on the active (this) engine until we are able - * to process the context switch away (and so mark the - * context as no longer in flight). That cannot have happened - * yet, otherwise we would not be hanging! - */ - spin_lock(&ve->base.active.lock); - GEM_BUG_ON(intel_context_inflight(rq->context) != engine); - GEM_BUG_ON(ve->request != rq); - ve->request = NULL; - spin_unlock(&ve->base.active.lock); - i915_request_put(rq); - - rq->engine = engine; - } - /* * Transfer this request onto the hold queue to prevent it * being resumbitted to HW (and potentially completed) before we have -- 2.11.0