[Intel-gfx] [PATCH 12/38] drm/i915: Reduce presumption of request ordering for barriers
Chris Wilson
chris at chris-wilson.co.uk
Fri Mar 1 14:03:38 UTC 2019
Currently we assume that we know the order in which requests run and so
can determine if we need to reissue a switch-to-kernel-context prior to
idling. That assumption does not hold for the future, so instead of
tracking which barriers have been used, simply determine if we have ever
switched away from the kernel context by using the engine and before
idling ensure that all engines that have been used since the last idle
are synchronously switched back to the kernel context for safety (and
else of shrinking memory while idle).
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 13 ++--
drivers/gpu/drm/i915/i915_gem_context.c | 66 +------------------
drivers/gpu/drm/i915/i915_gem_context.h | 3 +-
drivers/gpu/drm/i915/i915_gem_evict.c | 2 +-
drivers/gpu/drm/i915/i915_request.c | 1 +
drivers/gpu/drm/i915/intel_engine_cs.c | 5 ++
.../gpu/drm/i915/selftests/i915_gem_context.c | 3 +-
.../gpu/drm/i915/selftests/igt_flush_test.c | 2 +-
.../gpu/drm/i915/selftests/mock_gem_device.c | 4 ++
10 files changed, 28 insertions(+), 72 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0dd680cdb9ce..195e71bb4a4f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1994,6 +1994,7 @@ struct drm_i915_private {
struct list_head active_rings;
struct list_head closed_vma;
+ unsigned long active_engines;
u32 active_requests;
/**
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7ec2f68218fc..d17a99f59374 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2889,9 +2889,10 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915)
}
}
-static bool switch_to_kernel_context_sync(struct drm_i915_private *i915)
+static bool switch_to_kernel_context_sync(struct drm_i915_private *i915,
+ unsigned long mask)
{
- if (i915_gem_switch_to_kernel_context(i915))
+ if (i915_gem_switch_to_kernel_context(i915, mask))
return false;
if (i915_gem_wait_for_idle(i915,
@@ -2906,7 +2907,8 @@ static bool switch_to_kernel_context_sync(struct drm_i915_private *i915)
static bool load_power_context(struct drm_i915_private *i915)
{
- if (!switch_to_kernel_context_sync(i915))
+ /* Force loading the kernel context on all engines */
+ if (!switch_to_kernel_context_sync(i915, -1))
return false;
/*
@@ -2954,7 +2956,8 @@ i915_gem_idle_work_handler(struct work_struct *work)
if (!gt->active_requests && !work_pending(>->idle_work.work)) {
++gt->active_requests; /* don't requeue idle */
- if (!switch_to_kernel_context_sync(i915)) {
+ if (!switch_to_kernel_context_sync(i915,
+ i915->gt.active_engines)) {
dev_err(i915->drm.dev,
"Failed to idle engines, declaring wedged!\n");
GEM_TRACE_DUMP();
@@ -4411,7 +4414,7 @@ void i915_gem_suspend(struct drm_i915_private *i915)
* state. Fortunately, the kernel_context is disposable and we do
* not rely on its state.
*/
- if (!switch_to_kernel_context_sync(i915)) {
+ if (!switch_to_kernel_context_sync(i915, i915->gt.active_engines)) {
/* Forcibly cancel outstanding work and leave the gpu quiet. */
i915_gem_set_wedged(i915);
}
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 3c6edebd595b..004ffcfb305d 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -702,63 +702,10 @@ last_request_on_engine(struct i915_timeline *timeline,
return NULL;
}
-static bool engine_has_kernel_context_barrier(struct intel_engine_cs *engine)
-{
- struct drm_i915_private *i915 = engine->i915;
- const struct intel_context * const ce =
- to_intel_context(i915->kernel_context, engine);
- struct i915_timeline *barrier = ce->ring->timeline;
- struct intel_ring *ring;
- bool any_active = false;
-
- lockdep_assert_held(&i915->drm.struct_mutex);
- list_for_each_entry(ring, &i915->gt.active_rings, active_link) {
- struct i915_request *rq;
-
- rq = last_request_on_engine(ring->timeline, engine);
- if (!rq)
- continue;
-
- any_active = true;
-
- if (rq->hw_context == ce)
- continue;
-
- /*
- * Was this request submitted after the previous
- * switch-to-kernel-context?
- */
- if (!i915_timeline_sync_is_later(barrier, &rq->fence)) {
- GEM_TRACE("%s needs barrier for %llx:%lld\n",
- ring->timeline->name,
- rq->fence.context,
- rq->fence.seqno);
- return false;
- }
-
- GEM_TRACE("%s has barrier after %llx:%lld\n",
- ring->timeline->name,
- rq->fence.context,
- rq->fence.seqno);
- }
-
- /*
- * If any other timeline was still active and behind the last barrier,
- * then our last switch-to-kernel-context must still be queued and
- * will run last (leaving the engine in the kernel context when it
- * eventually idles).
- */
- if (any_active)
- return true;
-
- /* The engine is idle; check that it is idling in the kernel context. */
- return engine->last_retired_context == ce;
-}
-
-int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
+int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915,
+ unsigned long mask)
{
struct intel_engine_cs *engine;
- enum intel_engine_id id;
GEM_TRACE("awake?=%s\n", yesno(i915->gt.awake));
@@ -769,17 +716,11 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
if (i915_terminally_wedged(i915))
return 0;
- i915_retire_requests(i915);
-
- for_each_engine(engine, i915, id) {
+ for_each_engine_masked(engine, i915, mask, mask) {
struct intel_ring *ring;
struct i915_request *rq;
GEM_BUG_ON(!to_intel_context(i915->kernel_context, engine));
- if (engine_has_kernel_context_barrier(engine))
- continue;
-
- GEM_TRACE("emit barrier on %s\n", engine->name);
rq = i915_request_alloc(engine, i915->kernel_context);
if (IS_ERR(rq))
@@ -803,7 +744,6 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
i915_sw_fence_await_sw_fence_gfp(&rq->submit,
&prev->submit,
I915_FENCE_GFP);
- i915_timeline_sync_set(rq->timeline, &prev->fence);
}
i915_request_add(rq);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index be63666ffaac..c39dbb32a5c6 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -372,7 +372,8 @@ int i915_gem_context_open(struct drm_i915_private *i915,
void i915_gem_context_close(struct drm_file *file);
int i915_switch_context(struct i915_request *rq);
-int i915_gem_switch_to_kernel_context(struct drm_i915_private *dev_priv);
+int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915,
+ unsigned long engine_mask);
void i915_gem_context_release(struct kref *ctx_ref);
struct i915_gem_context *
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index 68d74c50ac39..7d8e90dfca84 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -62,7 +62,7 @@ static int ggtt_flush(struct drm_i915_private *i915)
* the hopes that we can then remove contexts and the like only
* bound by their active reference.
*/
- err = i915_gem_switch_to_kernel_context(i915);
+ err = i915_gem_switch_to_kernel_context(i915, i915->gt.active_engines);
if (err)
return err;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index bcf3c1a155e2..9d111eedad5a 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1066,6 +1066,7 @@ void i915_request_add(struct i915_request *request)
GEM_TRACE("marking %s as active\n", ring->timeline->name);
list_add(&ring->active_link, &request->i915->gt.active_rings);
}
+ request->i915->gt.active_engines |= request->engine->mask;
request->emitted_jiffies = jiffies;
/*
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 8226871c7781..e283ea693576 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1116,6 +1116,9 @@ bool intel_engine_has_kernel_context(const struct intel_engine_cs *engine)
lockdep_assert_held(&engine->i915->drm.struct_mutex);
+ if (!engine->context_size)
+ return true;
+
/*
* Check the last context seen by the engine. If active, it will be
* the last request that remains in the timeline. When idle, it is
@@ -1215,6 +1218,8 @@ void intel_engines_park(struct drm_i915_private *i915)
i915_gem_batch_pool_fini(&engine->batch_pool);
engine->execlists.no_priolist = false;
}
+
+ i915->gt.active_engines = 0;
}
/**
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index 1c608b60c55c..7ae5033457b6 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -1512,7 +1512,8 @@ static int __igt_switch_to_kernel_context(struct drm_i915_private *i915,
}
}
- err = i915_gem_switch_to_kernel_context(i915);
+ err = i915_gem_switch_to_kernel_context(i915,
+ i915->gt.active_engines);
if (err)
return err;
diff --git a/drivers/gpu/drm/i915/selftests/igt_flush_test.c b/drivers/gpu/drm/i915/selftests/igt_flush_test.c
index e0d3122fd35a..94aee4071a66 100644
--- a/drivers/gpu/drm/i915/selftests/igt_flush_test.c
+++ b/drivers/gpu/drm/i915/selftests/igt_flush_test.c
@@ -14,7 +14,7 @@ int igt_flush_test(struct drm_i915_private *i915, unsigned int flags)
cond_resched();
if (flags & I915_WAIT_LOCKED &&
- i915_gem_switch_to_kernel_context(i915)) {
+ i915_gem_switch_to_kernel_context(i915, i915->gt.active_engines)) {
pr_err("Failed to switch back to kernel context; declaring wedged\n");
i915_gem_set_wedged(i915);
}
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 8581cf5e0e8c..ce384e659220 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -109,6 +109,10 @@ static void mock_retire_work_handler(struct work_struct *work)
static void mock_idle_work_handler(struct work_struct *work)
{
+ struct drm_i915_private *i915 =
+ container_of(work, typeof(*i915), gt.idle_work.work);
+
+ i915->gt.active_engines = 0;
}
static int pm_domain_resume(struct device *dev)
--
2.20.1
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