From 94523024363b373584bfb0a8eed9ba194d41b4d5 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 17 Jan 2020 11:32:59 +0000 Subject: [PATCH] drm/i915/gt: Report the currently active execlists request Since commit 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy"), we prune the engine->active.requests list prior to preemption, thus removing the trace of the currently executing request. If that request hangs rather than be preempted, we conclude that no active request was on the GPU. Fortunately, this only impacts our debugging, and not our means of hang detection or recovery. v2: Use from to check the current iterator before continuing, and report active as NULL if the current request is already completed. References: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20200117113259.3023890-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_engine_cs.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index 06ff769..2d0ef5f 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -1657,6 +1657,23 @@ intel_engine_find_active_request(struct intel_engine_cs *engine) * we only care about the snapshot of this moment. */ lockdep_assert_held(&engine->active.lock); + + rcu_read_lock(); + request = execlists_active(&engine->execlists); + if (request) { + struct intel_timeline *tl = request->context->timeline; + + list_for_each_entry_from_reverse(request, &tl->requests, link) { + if (i915_request_completed(request)) + break; + + active = request; + } + } + rcu_read_unlock(); + if (active) + return active; + list_for_each_entry(request, &engine->active.requests, sched.link) { if (i915_request_completed(request)) continue; -- 2.7.4