From d9516d744d1d94395c10a97b3ac8155c114e044d Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 17 Jan 2020 11:32:59 +0000
Subject: drm/i915/gt: Report the currently active execlists request
Git-commit: 94523024363b373584bfb0a8eed9ba194d41b4d5
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
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 <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200117113259.3023890-1-chris@chris-wilson.co.uk
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
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 06ff7695fa29..2d0ef5fc6748 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;
--
2.28.0