[RFC 1/6] drm/i915: Individual request cancellation
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Fri Mar 12 15:46:17 UTC 2021
From: Chris Wilson <chris at chris-wilson.co.uk>
Currently, we cancel outstanding requests within a context when the
context is closed. We may also want to cancel individual requests using
the same graceful preemption mechanism.
v2 (Tvrtko):
* Cancel waiters carefully considering no timeline lock and RCU.
* Fixed selftests.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
.../gpu/drm/i915/gt/intel_engine_heartbeat.c | 1 +
.../drm/i915/gt/intel_execlists_submission.c | 9 +-
drivers/gpu/drm/i915/i915_request.c | 77 ++++-
drivers/gpu/drm/i915/i915_request.h | 4 +-
drivers/gpu/drm/i915/selftests/i915_request.c | 275 ++++++++++++++++++
5 files changed, 360 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
index 0b062fad1837..e2fb3ae2aaf3 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
@@ -314,6 +314,7 @@ int intel_engine_pulse(struct intel_engine_cs *engine)
mutex_unlock(&ce->timeline->mutex);
}
+ intel_engine_flush_scheduler(engine);
intel_engine_pm_put(engine);
return err;
}
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 85ff5fe861b4..4c2acb5a6c0a 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -421,6 +421,11 @@ static void reset_active(struct i915_request *rq,
ce->lrc.lrca = lrc_update_regs(ce, engine, head);
}
+static bool bad_request(const struct i915_request *rq)
+{
+ return rq->fence.error && i915_request_started(rq);
+}
+
static struct intel_engine_cs *
__execlists_schedule_in(struct i915_request *rq)
{
@@ -433,7 +438,7 @@ __execlists_schedule_in(struct i915_request *rq)
!intel_engine_has_heartbeat(engine)))
intel_context_set_banned(ce);
- if (unlikely(intel_context_is_banned(ce)))
+ if (unlikely(intel_context_is_banned(ce) || bad_request(rq)))
reset_active(rq, engine);
if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
@@ -1112,7 +1117,7 @@ static unsigned long active_preempt_timeout(struct intel_engine_cs *engine,
return 0;
/* Force a fast reset for terminated contexts (ignoring sysfs!) */
- if (unlikely(intel_context_is_banned(rq->context)))
+ if (unlikely(intel_context_is_banned(rq->context) || bad_request(rq)))
return 1;
return READ_ONCE(engine->props.preempt_timeout_ms);
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index e7b4c4bc41a6..fb9c5bb1fe41 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -33,7 +33,10 @@
#include "gem/i915_gem_context.h"
#include "gt/intel_breadcrumbs.h"
#include "gt/intel_context.h"
+#include "gt/intel_engine.h"
+#include "gt/intel_engine_heartbeat.h"
#include "gt/intel_gpu_commands.h"
+#include "gt/intel_reset.h"
#include "gt/intel_ring.h"
#include "gt/intel_rps.h"
@@ -429,20 +432,22 @@ void __i915_request_skip(struct i915_request *rq)
rq->infix = rq->postfix;
}
-void i915_request_set_error_once(struct i915_request *rq, int error)
+bool i915_request_set_error_once(struct i915_request *rq, int error)
{
int old;
GEM_BUG_ON(!IS_ERR_VALUE((long)error));
if (i915_request_signaled(rq))
- return;
+ return false;
old = READ_ONCE(rq->fence.error);
do {
if (fatal_error(old))
- return;
+ return false;
} while (!try_cmpxchg(&rq->fence.error, &old, error));
+
+ return true;
}
struct i915_request *i915_request_mark_eio(struct i915_request *rq)
@@ -609,6 +614,72 @@ void i915_request_unsubmit(struct i915_request *request)
spin_unlock_irqrestore(&se->lock, flags);
}
+static struct intel_engine_cs *active_engine(struct i915_request *rq)
+{
+ struct intel_engine_cs *engine, *locked;
+
+ locked = READ_ONCE(rq->engine);
+ spin_lock_irq(&locked->sched.lock);
+ while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {
+ spin_unlock(&locked->sched.lock);
+ locked = engine;
+ spin_lock(&locked->sched.lock);
+ }
+
+ engine = NULL;
+ if (i915_request_is_active(rq) && !__i915_request_is_complete(rq))
+ engine = locked;
+
+ spin_unlock_irq(&locked->sched.lock);
+
+ return engine;
+}
+
+static void __cancel_request(struct i915_request *rq)
+{
+ struct intel_engine_cs *engine = active_engine(rq);
+
+ if (engine && intel_engine_pulse(engine))
+ intel_gt_handle_error(engine->gt, engine->mask, 0,
+ "request cancellation by %s",
+ current->comm);
+}
+
+void i915_request_cancel(struct i915_request *rq, int error)
+{
+ if (!i915_request_set_error_once(rq, error))
+ return;
+
+ set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags);
+
+ if (i915_sw_fence_signaled(&rq->submit)) {
+ struct i915_dependency *p;
+
+restart:
+ rcu_read_lock();
+ for_each_waiter(p, rq) {
+ struct i915_request *w =
+ container_of(p->waiter, typeof(*w), sched);
+
+ if (__i915_request_is_complete(w) ||
+ fatal_error(w->fence.error))
+ continue;
+
+ w = i915_request_get(w);
+ rcu_read_unlock();
+ /* Recursion bound by the number of engines */
+ i915_request_cancel(w, error);
+ i915_request_put(w);
+
+ /* Restart after having to drop rcu lock. */
+ goto restart;
+ }
+ rcu_read_unlock();
+ }
+
+ __cancel_request(rq);
+}
+
static int __i915_sw_fence_call
submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
{
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index dd10a6db3d21..64869a313b3e 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -312,7 +312,7 @@ struct i915_request * __must_check
i915_request_create(struct intel_context *ce);
void __i915_request_skip(struct i915_request *rq);
-void i915_request_set_error_once(struct i915_request *rq, int error);
+bool i915_request_set_error_once(struct i915_request *rq, int error);
struct i915_request *i915_request_mark_eio(struct i915_request *rq);
struct i915_request *__i915_request_commit(struct i915_request *request);
@@ -368,6 +368,8 @@ void i915_request_submit(struct i915_request *request);
void __i915_request_unsubmit(struct i915_request *request);
void i915_request_unsubmit(struct i915_request *request);
+void i915_request_cancel(struct i915_request *rq, int error);
+
long i915_request_wait(struct i915_request *rq,
unsigned int flags,
long timeout)
diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 8035ea7565ed..e63609ec5b97 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -608,6 +608,280 @@ static int live_nop_request(void *arg)
return err;
}
+static int __cancel_inactive(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+ struct igt_spinner spin;
+ struct i915_request *rq;
+ int err = 0;
+
+ if (igt_spinner_init(&spin, engine->gt))
+ return -ENOMEM;
+
+ ce = intel_context_create(engine);
+ if (IS_ERR(ce)) {
+ err = PTR_ERR(ce);
+ goto out_spin;
+ }
+
+ rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto out_ce;
+ }
+
+ pr_debug("%s: Cancelling inactive request\n", engine->name);
+ i915_request_cancel(rq, -EINTR);
+ i915_request_get(rq);
+ i915_request_add(rq);
+
+ if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+ struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+ pr_err("%s: Failed to cancel inactive request\n", engine->name);
+ intel_engine_dump(engine, &p, "%s\n", engine->name);
+ err = -ETIME;
+ goto out_rq;
+ }
+
+ if (rq->fence.error != -EINTR) {
+ pr_err("%s: fence not cancelled (%u)\n",
+ engine->name, rq->fence.error);
+ err = -EINVAL;
+ }
+
+out_rq:
+ i915_request_put(rq);
+out_ce:
+ intel_context_put(ce);
+out_spin:
+ igt_spinner_fini(&spin);
+ if (err)
+ pr_err("%s: __cancel_inactive error %d\n", engine->name, err);
+ return err;
+}
+
+static int __cancel_active(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+ struct igt_spinner spin;
+ struct i915_request *rq;
+ int err = 0;
+
+ if (igt_spinner_init(&spin, engine->gt))
+ return -ENOMEM;
+
+ ce = intel_context_create(engine);
+ if (IS_ERR(ce)) {
+ err = PTR_ERR(ce);
+ goto out_spin;
+ }
+
+ rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto out_ce;
+ }
+
+ pr_debug("%s: Cancelling active request\n", engine->name);
+ i915_request_get(rq);
+ i915_request_add(rq);
+ if (!igt_wait_for_spinner(&spin, rq)) {
+ struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+ pr_err("Failed to start spinner on %s\n", engine->name);
+ intel_engine_dump(engine, &p, "%s\n", engine->name);
+ err = -ETIME;
+ goto out_rq;
+ }
+ i915_request_cancel(rq, -EINTR);
+
+ if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+ struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+ pr_err("%s: Failed to cancel active request\n", engine->name);
+ intel_engine_dump(engine, &p, "%s\n", engine->name);
+ err = -ETIME;
+ goto out_rq;
+ }
+
+ if (rq->fence.error != -EINTR) {
+ pr_err("%s: fence not cancelled (%u)\n",
+ engine->name, rq->fence.error);
+ err = -EINVAL;
+ }
+
+out_rq:
+ i915_request_put(rq);
+out_ce:
+ intel_context_put(ce);
+out_spin:
+ igt_spinner_fini(&spin);
+ if (err)
+ pr_err("%s: __cancel_active error %d\n", engine->name, err);
+ return err;
+}
+
+static int __cancel_active_chain(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+ struct igt_spinner spin;
+ struct i915_request *rq[2];
+ int err = 0;
+
+ if (igt_spinner_init(&spin, engine->gt))
+ return -ENOMEM;
+
+ ce = intel_context_create(engine);
+ if (IS_ERR(ce)) {
+ err = PTR_ERR(ce);
+ goto out_spin;
+ }
+
+ rq[0] = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+ if (IS_ERR(rq[0])) {
+ err = PTR_ERR(rq[0]);
+ goto out_ce;
+ }
+ i915_request_get(rq[0]);
+ i915_request_add(rq[0]);
+
+ rq[1] = intel_context_create_request(ce);
+ if (IS_ERR(rq[1])) {
+ err = PTR_ERR(rq[1]);
+ goto out_spinner;
+ }
+ i915_request_get(rq[1]);
+ i915_request_add(rq[1]);
+
+ pr_debug("%s: Cancelling active chain\n", engine->name);
+ intel_engine_flush_scheduler(engine);
+ i915_request_cancel(rq[0], -EINTR);
+ igt_spinner_end(&spin);
+
+ if (i915_request_wait(rq[1], 0, HZ / 5) < 0) {
+ struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+ pr_err("%s: Failed to cancel chained request\n", engine->name);
+ intel_engine_dump(engine, &p, "%s\n", engine->name);
+ err = -ETIME;
+ goto out_waiter;
+ }
+
+ if (rq[0]->fence.error != -EINTR) {
+ pr_err("%s: first fence not cancelled (%u)\n",
+ engine->name, rq[0]->fence.error);
+ err = -EINVAL;
+ }
+
+ if (rq[1]->fence.error != -EINTR) {
+ pr_err("%s: second fence not cancelled (%u)\n",
+ engine->name, rq[1]->fence.error);
+ err = -EINVAL;
+ }
+
+out_waiter:
+ i915_request_put(rq[1]);
+out_spinner:
+ i915_request_put(rq[0]);
+out_ce:
+ intel_context_put(ce);
+out_spin:
+ igt_spinner_fini(&spin);
+ if (err)
+ pr_err("%s: __cancel_active_chain error %d\n",
+ engine->name, err);
+ return err;
+}
+
+static int __cancel_completed(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+ struct igt_spinner spin;
+ struct i915_request *rq;
+ int err = 0;
+
+ if (igt_spinner_init(&spin, engine->gt))
+ return -ENOMEM;
+
+ ce = intel_context_create(engine);
+ if (IS_ERR(ce)) {
+ err = PTR_ERR(ce);
+ goto out_spin;
+ }
+
+ rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto out_ce;
+ }
+ igt_spinner_end(&spin);
+ i915_request_get(rq);
+ i915_request_add(rq);
+
+ if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+ err = -ETIME;
+ goto out_rq;
+ }
+
+ pr_debug("%s: Cancelling completed request\n", engine->name);
+ i915_request_cancel(rq, -EINTR);
+ if (rq->fence.error) {
+ pr_err("%s: fence not cancelled (%u)\n",
+ engine->name, rq->fence.error);
+ err = -EINVAL;
+ }
+
+out_rq:
+ i915_request_put(rq);
+out_ce:
+ intel_context_put(ce);
+out_spin:
+ igt_spinner_fini(&spin);
+ if (err)
+ pr_err("%s: __cancel_completed error %d\n", engine->name, err);
+ return err;
+}
+
+static int live_cancel_request(void *arg)
+{
+ struct drm_i915_private *i915 = arg;
+ struct intel_engine_cs *engine;
+
+ /*
+ * Check cancellation of requests. We expect to be able to immediately
+ * cancel active requests, even if they are currently on the GPU.
+ */
+
+ for_each_uabi_engine(engine, i915) {
+ struct igt_live_test t;
+ int err, err2;
+
+ if (!intel_engine_has_preemption(engine))
+ continue;
+
+ err = igt_live_test_begin(&t, i915, __func__, engine->name);
+ if (err)
+ return err;
+
+ err = __cancel_inactive(engine);
+ if (err == 0)
+ err = __cancel_active(engine);
+ if (err == 0)
+ err = __cancel_active_chain(engine);
+ if (err == 0)
+ err = __cancel_completed(engine);
+
+ err2 = igt_live_test_end(&t);
+ if (err)
+ return err;
+ if (err2)
+ return err2;
+ }
+
+ return 0;
+}
+
static struct i915_vma *empty_batch(struct drm_i915_private *i915)
{
struct drm_i915_gem_object *obj;
@@ -1485,6 +1759,7 @@ int i915_request_live_selftests(struct drm_i915_private *i915)
SUBTEST(live_sequential_engines),
SUBTEST(live_parallel_engines),
SUBTEST(live_empty_request),
+ SUBTEST(live_cancel_request),
SUBTEST(live_breadcrumbs_smoketest),
};
--
2.27.0
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