/* Check that the context wasn't destroyed before submission */
if (likely(!intel_context_is_closed(eb->context))) {
attr = eb->gem_context->sched;
-
- /*
- * Boost actual workloads past semaphores!
- *
- * With semaphores we spin on one engine waiting for another,
- * simply to reduce the latency of starting our work when
- * the signaler completes. However, if there is any other
- * work that we could be doing on this engine instead, that
- * is better utilisation and will reduce the overall duration
- * of the current work. To avoid PI boosting a semaphore
- * far in the distance past over useful work, we keep a history
- * of any semaphore use along our dependency chain.
- */
- if (!(rq->sched.flags & I915_SCHED_HAS_SEMAPHORE_CHAIN))
- attr.priority |= I915_PRIORITY_NOSEMAPHORE;
} else {
/* Serialise with context_close via the add_to_timeline */
i915_request_set_error_once(rq, -ENOENT);
if (i915_request_has_nopreempt(rq))
prio = I915_PRIORITY_UNPREEMPTABLE;
- /*
- * On unwinding the active request, we give it a priority bump
- * if it has completed waiting on any semaphore. If we know that
- * the request has already started, we can prevent an unwanted
- * preempt-to-idle cycle by taking that into account now.
- */
- if (__i915_request_has_started(rq))
- prio |= I915_PRIORITY_NOSEMAPHORE;
-
return prio;
}
/* Opencode i915_request_add() so we can keep the timeline locked. */
__i915_request_commit(rq);
+ rq->sched.attr.priority = I915_PRIORITY_BARRIER;
__i915_request_queue(rq, NULL);
timeout = i915_request_wait(rq, 0, HZ / 10);
I915_PRIORITY_DISPLAY,
};
-#define I915_USER_PRIORITY_SHIFT 1
+#define I915_USER_PRIORITY_SHIFT 0
#define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT)
#define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT)
#define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1)
-#define I915_PRIORITY_NOSEMAPHORE ((u8)BIT(0))
-
/* Smallest priority value that cannot be bumped. */
#define I915_PRIORITY_INVALID (INT_MIN | (u8)I915_PRIORITY_MASK)
}
spin_unlock_irq(&signal->lock);
- /* Copy across semaphore status as we need the same behaviour */
- rq->sched.flags |= signal->sched.flags;
return 0;
}
spin_unlock(&request->lock);
/* We've already spun, don't charge on resubmitting. */
- if (request->sched.semaphores && i915_request_started(request)) {
- request->sched.attr.priority |= I915_PRIORITY_NOSEMAPHORE;
+ if (request->sched.semaphores && i915_request_started(request))
request->sched.semaphores = 0;
- }
/*
* We don't need to wake_up any waiters on request->execute, they
return NOTIFY_DONE;
}
-static void irq_semaphore_cb(struct irq_work *wrk)
-{
- struct i915_request *rq =
- container_of(wrk, typeof(*rq), semaphore_work);
-
- i915_schedule_bump_priority(rq, I915_PRIORITY_NOSEMAPHORE);
- i915_request_put(rq);
-}
-
static int __i915_sw_fence_call
semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
{
switch (state) {
case FENCE_COMPLETE:
- if (!(READ_ONCE(rq->sched.attr.priority) & I915_PRIORITY_NOSEMAPHORE)) {
- i915_request_get(rq);
- init_irq_work(&rq->semaphore_work, irq_semaphore_cb);
- irq_work_queue(&rq->semaphore_work);
- }
break;
case FENCE_FREE:
gfp_t gfp)
{
const intel_engine_mask_t mask = READ_ONCE(from->engine)->mask;
+ struct i915_sw_fence *wait = &to->submit;
if (!intel_context_use_semaphores(to->context))
goto await_fence;
goto await_fence;
to->sched.semaphores |= mask;
- to->sched.flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN;
- return 0;
+ wait = &to->semaphore;
await_fence:
- return i915_sw_fence_await_dma_fence(&to->submit,
+ return i915_sw_fence_await_dma_fence(wait,
&from->fence, 0,
I915_FENCE_GFP);
}
if (ret < 0)
return ret;
- if (to->sched.flags & I915_SCHED_HAS_SEMAPHORE_CHAIN) {
- ret = i915_sw_fence_await_dma_fence(&to->semaphore,
- &from->fence, 0,
- I915_FENCE_GFP);
- if (ret < 0)
- return ret;
- }
-
- if (from->sched.flags & I915_SCHED_HAS_EXTERNAL_CHAIN)
- to->sched.flags |= I915_SCHED_HAS_EXTERNAL_CHAIN;
-
return 0;
}
attr = ctx->sched;
rcu_read_unlock();
- if (!(rq->sched.flags & I915_SCHED_HAS_SEMAPHORE_CHAIN))
- attr.priority |= I915_PRIORITY_NOSEMAPHORE;
-
__i915_request_queue(rq, &attr);
mutex_unlock(&tl->mutex);
};
struct list_head execute_cb;
struct i915_sw_fence semaphore;
- struct irq_work semaphore_work;
/*
* A list of everyone we wait upon, and everyone who waits upon us.
GEM_BUG_ON(rb_first_cached(&execlists->queue) !=
rb_first(&execlists->queue.rb_root));
- last_prio = (INT_MAX >> I915_USER_PRIORITY_SHIFT) + 1;
+ last_prio = INT_MAX;
for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) {
const struct i915_priolist *p = to_priolist(rb);
- GEM_BUG_ON(p->priority >= last_prio);
+ GEM_BUG_ON(p->priority > last_prio);
last_prio = p->priority;
GEM_BUG_ON(!p->used);
dep->waiter = node;
dep->flags = flags;
- /* Keep track of whether anyone on this chain has a semaphore */
- if (signal->flags & I915_SCHED_HAS_SEMAPHORE_CHAIN &&
- !node_started(signal))
- node->flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN;
-
/* All set, now publish. Beware the lockless walkers. */
list_add_rcu(&dep->signal_link, &node->signalers_list);
list_add_rcu(&dep->wait_link, &signal->waiters_list);
+ /* Propagate the chains */
+ node->flags |= signal->flags;
ret = true;
}
struct list_head link;
struct i915_sched_attr attr;
unsigned int flags;
-#define I915_SCHED_HAS_SEMAPHORE_CHAIN BIT(0)
-#define I915_SCHED_HAS_EXTERNAL_CHAIN BIT(1)
+#define I915_SCHED_HAS_EXTERNAL_CHAIN BIT(0)
intel_engine_mask_t semaphores;
};