drm/i915/execlists: Cache the priolist when rescheduling

When rescheduling a change of dependencies, they all need to be added to
the same priolist (at least the ones on the same engine!). Since we
likely want to move a batch of requests, keep the priolist around.

v2: Throw in an assert to catch trivial errors quickly.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508003046.2633-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index bf9a44dae558586e91a9fb15c8c28962dee37191..046adf397a717f91d88662ba1c53f1a4c80b54c2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -346,6 +346,7 @@ static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
                        p = lookup_priolist(engine, last_prio);
                }
 
+               GEM_BUG_ON(p->priority != rq_prio(rq));
                list_add(&rq->sched.link, &p->requests);
        }
 }
@@ -1198,7 +1199,8 @@ sched_lock_engine(struct i915_sched_node *node, struct intel_engine_cs *locked)
 static void execlists_schedule(struct i915_request *request,
                               const struct i915_sched_attr *attr)
 {
-       struct intel_engine_cs *engine;
+       struct i915_priolist *uninitialized_var(pl);
+       struct intel_engine_cs *engine, *last;
        struct i915_dependency *dep, *p;
        struct i915_dependency stack;
        const int prio = attr->priority;
@@ -1271,6 +1273,7 @@ static void execlists_schedule(struct i915_request *request,
                __list_del_entry(&stack.dfs_link);
        }
 
+       last = NULL;
        engine = request->engine;
        spin_lock_irq(&engine->timeline.lock);
 
@@ -1287,8 +1290,12 @@ static void execlists_schedule(struct i915_request *request,
 
                node->attr.priority = prio;
                if (!list_empty(&node->link)) {
-                       __list_del_entry(&node->link);
-                       queue_request(engine, node, prio);
+                       if (last != engine) {
+                               pl = lookup_priolist(engine, prio);
+                               last = engine;
+                       }
+                       GEM_BUG_ON(pl->priority != prio);
+                       list_move_tail(&node->link, &pl->requests);
                }
 
                if (prio > engine->execlists.queue_priority &&