[PATCH 10/14] drm/i915/execlists: Don't apply priority boost for resets

Chris Wilson
2019-05-01T11:45:54Z

Do not treat reset as a normal preemption event and avoid giving the
guilty request a priority boost for simply being active at the time of
reset.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/intel_lrc.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 35aae7b5c6b9..aa03dd0760e9 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -370,11 +370,11 @@ static void unwind_wa_tail(struct i915_request *rq)
}

static struct i915_request *
-__unwind_incomplete_requests(struct intel_engine_cs *engine)
+__unwind_incomplete_requests(struct intel_engine_cs *engine, int boost)
{
struct i915_request *rq, *rn, *active = NULL;
struct list_head *uninitialized_var(pl);
- int prio = I915_PRIORITY_INVALID | ACTIVE_PRIORITY;
+ int prio = I915_PRIORITY_INVALID | boost;

lockdep_assert_held(&engine->timeline.lock);

@@ -418,8 +418,9 @@ __unwind_incomplete_requests(struct intel_engine_cs *engine)
* in the priority queue, but they will not gain immediate access to
* the GPU.
*/
- if (~prio & ACTIVE_PRIORITY && __i915_request_has_started(active)) {
- prio |= ACTIVE_PRIORITY;
+ if (~prio & boost && __i915_request_has_started(active)) {
+ prio |= boost;
+ GEM_BUG_ON(active->sched.attr.priority >= prio);
active->sched.attr.priority = prio;
list_move_tail(&active->sched.link,
i915_sched_lookup_priolist(engine, prio));
@@ -434,7 +435,7 @@ execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists)
struct intel_engine_cs *engine =
container_of(execlists, typeof(*engine), execlists);

- return __unwind_incomplete_requests(engine);
+ return __unwind_incomplete_requests(engine, 0);
}

static inline void
@@ -655,7 +656,8 @@ static void complete_preempt_context(struct intel_engine_execlists *execlists)
execlists_cancel_port_requests(execlists);
__unwind_incomplete_requests(container_of(execlists,
struct intel_engine_cs,
- execlists));
+ execlists),
+ ACTIVE_PRIORITY);
}

static void execlists_dequeue(struct intel_engine_cs *engine)
@@ -1908,7 +1910,7 @@ static void __execlists_reset(struct intel_engine_cs *engine, bool stalled)
execlists_cancel_port_requests(execlists);

/* Push back any incomplete requests for replay after the reset. */
- rq = __unwind_incomplete_requests(engine);
+ rq = __unwind_incomplete_requests(engine, 0);
if (!rq)
goto out_replay;

--
2.20.1