EGL_NV_realtime_priority?

Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_context.c    | 22 ++++++++
 drivers/gpu/drm/i915/i915_gem_context.h    | 13 +++++
 drivers/gpu/drm/i915/i915_request.c        |  8 ++-
 drivers/gpu/drm/i915/intel_lrc.c           |  2 +-
 drivers/gpu/drm/i915/selftests/intel_lrc.c | 85 ++++++++++++++++++++++++++++++
 include/uapi/drm/i915_drm.h                | 12 +++++
 6 files changed, 139 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c 
b/drivers/gpu/drm/i915/i915_gem_context.c
index 5cfac0255758..dfb0a2b698c3 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -749,6 +749,15 @@ int i915_gem_context_getparam_ioctl(struct drm_device 
*dev, void *data,
        case I915_CONTEXT_PARAM_PRIORITY:
                args->value = ctx->priority;
                break;
+       case I915_CONTEXT_PARAM_PREEMPT_TIMEOUT:
+               if (!(to_i915(dev)->caps.scheduler & 
I915_SCHEDULER_CAP_PREEMPTION))
+                       ret = -ENODEV;
+               else if (args->size)
+                       ret = -EINVAL;
+               else
+                       args->value = ctx->preempt_timeout;
+               break;
+
        default:
                ret = -EINVAL;
                break;
@@ -824,6 +833,19 @@ int i915_gem_context_setparam_ioctl(struct drm_device 
*dev, void *data,
                }
                break;
 
+       case I915_CONTEXT_PARAM_PREEMPT_TIMEOUT:
+               if (args->size)
+                       ret = -EINVAL;
+               else if (args->value >= NSEC_PER_SEC)
+                       ret = -EINVAL;
+               else if (!(to_i915(dev)->caps.scheduler & 
I915_SCHEDULER_CAP_PREEMPTION))
+                       ret = -ENODEV;
+               else if (args->value && !capable(CAP_SYS_ADMIN))
+                       ret = -EPERM;
+               else
+                       ctx->preempt_timeout = args->value;
+               break;
+
        default:
                ret = -EINVAL;
                break;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h 
b/drivers/gpu/drm/i915/i915_gem_context.h
index 7854262ddfd9..74d4cadd729e 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -150,6 +150,19 @@ struct i915_gem_context {
         */
        int priority;
 
+       /**
+        * @preempt_timeout: QoS guarantee for the high priority context
+        *
+        * Some clients need a guarantee that they will start executing
+        * within a certain window, even at the expense of others. This entails
+        * that if a preemption request is not honoured by the active context
+        * within the timeout, we will reset the GPU to evict the hog and
+        * run the high priority context instead.
+        *
+        * Timeout is stored in nanoseconds; exclusive max of 1s.
+        */
+       u32 preempt_timeout;
+
        /** ggtt_offset_bias: placement restriction for context objects */
        u32 ggtt_offset_bias;
 
diff --git a/drivers/gpu/drm/i915/i915_request.c 
b/drivers/gpu/drm/i915/i915_request.c
index cdda3ebd51e2..eae807e56723 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1107,8 +1107,12 @@ void __i915_request_add(struct i915_request *request, 
bool flush_caches)
         * run at the earliest possible convenience.
         */
        rcu_read_lock();
-       if (engine->schedule)
-               engine->schedule(request, request->ctx->priority, 0);
+       if (engine->schedule) {
+               unsigned int timeout = request->ctx->preempt_timeout;
+               int priority = request->ctx->priority;
+
+               engine->schedule(request, priority, timeout);
+       }
        rcu_read_unlock();
 
        local_bh_disable();
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 06a4815f5f31..e87181f88f96 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1212,7 +1212,7 @@ static void execlists_submit_request(struct i915_request 
*request)
        spin_lock_irqsave(&engine->timeline->lock, flags);
 
        queue_request(engine, &request->priotree, rq_prio(request));
-       submit_queue(engine, rq_prio(request), 0);
+       submit_queue(engine, rq_prio(request), request->ctx->preempt_timeout);
 
        GEM_BUG_ON(!engine->execlists.first);
        GEM_BUG_ON(list_empty(&request->priotree.link));
diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c 
b/drivers/gpu/drm/i915/selftests/intel_lrc.c
index 1970a4658c5c..121180b87fd7 100644
--- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
@@ -783,6 +783,90 @@ static int live_late_preempt_timeout(void *arg)
        goto err_ctx_lo;
 }
 
+static int live_context_preempt_timeout(void *arg)
+{
+       struct drm_i915_private *i915 = arg;
+       struct i915_gem_context *ctx_hi, *ctx_lo;
+       struct spinner spin_hi, spin_lo;
+       struct intel_engine_cs *engine;
+       enum intel_engine_id id;
+       int err = -ENOMEM;
+
+       if (!HAS_LOGICAL_RING_PREEMPTION(i915))
+               return 0;
+
+       mutex_lock(&i915->drm.struct_mutex);
+
+       if (spinner_init(&spin_hi, i915))
+               goto err_unlock;
+
+       if (spinner_init(&spin_lo, i915))
+               goto err_spin_hi;
+
+       ctx_hi = kernel_context(i915);
+       if (!ctx_hi)
+               goto err_spin_lo;
+       ctx_hi->priority = I915_CONTEXT_MAX_USER_PRIORITY;
+       ctx_hi->preempt_timeout = 50 * 1000; /* 50us */
+
+       ctx_lo = kernel_context(i915);
+       if (!ctx_lo)
+               goto err_ctx_hi;
+       ctx_lo->priority = I915_CONTEXT_MIN_USER_PRIORITY;
+
+       for_each_engine(engine, i915, id) {
+               struct i915_request *rq;
+
+               rq = spinner_create_request(&spin_lo, ctx_lo, engine, MI_NOOP);
+               if (IS_ERR(rq)) {
+                       err = PTR_ERR(rq);
+                       goto err_ctx_lo;
+               }
+
+               i915_request_add(rq);
+               if (!wait_for_spinner(&spin_lo, rq)) {
+                       i915_gem_set_wedged(i915);
+                       err = -EIO;
+                       goto err_ctx_lo;
+               }
+
+               rq = spinner_create_request(&spin_hi, ctx_hi, engine, MI_NOOP);
+               if (IS_ERR(rq)) {
+                       spinner_end(&spin_lo);
+                       err = PTR_ERR(rq);
+                       goto err_ctx_lo;
+               }
+
+               i915_request_add(rq);
+               if (!wait_for_spinner(&spin_hi, rq)) {
+                       i915_gem_set_wedged(i915);
+                       err = -EIO;
+                       goto err_ctx_lo;
+               }
+
+               spinner_end(&spin_hi);
+               spinner_end(&spin_lo);
+               if (flush_test(i915, I915_WAIT_LOCKED)) {
+                       err = -EIO;
+                       goto err_ctx_lo;
+               }
+       }
+
+       err = 0;
+err_ctx_lo:
+       kernel_context_close(ctx_lo);
+err_ctx_hi:
+       kernel_context_close(ctx_hi);
+err_spin_lo:
+       spinner_fini(&spin_lo);
+err_spin_hi:
+       spinner_fini(&spin_hi);
+err_unlock:
+       flush_test(i915, I915_WAIT_LOCKED);
+       mutex_unlock(&i915->drm.struct_mutex);
+       return err;
+}
+
 int intel_execlists_live_selftests(struct drm_i915_private *i915)
 {
        static const struct i915_subtest tests[] = {
@@ -792,6 +876,7 @@ int intel_execlists_live_selftests(struct drm_i915_private 
*i915)
                SUBTEST(live_preempt_timeout),
                SUBTEST(live_preempt_reset),
                SUBTEST(live_late_preempt_timeout),
+               SUBTEST(live_context_preempt_timeout),
        };
        return i915_subtests(tests, i915);
 }
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 7f5634ce8e88..6f10bbe90304 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1456,6 +1456,18 @@ struct drm_i915_gem_context_param {
 #define   I915_CONTEXT_MAX_USER_PRIORITY       1023 /* inclusive */
 #define   I915_CONTEXT_DEFAULT_PRIORITY                0
 #define   I915_CONTEXT_MIN_USER_PRIORITY       -1023 /* inclusive */
+
+/*
+ * I915_CONTEXT_PARAM_PREEMPT_TIMEOUT:
+ *
+ * Preemption timeout give in nanoseconds.
+ *
+ * Only allowed for privileged clients (CAP_SYS_ADMIN), this property allows
+ * the preempting context to kick out a GPU hog using a GPU reset if they do
+ * not honour the preemption request in time.
+ */
+#define I915_CONTEXT_PARAM_PREEMPT_TIMEOUT     0x7
+
        __u64 value;
 };
 
-- 
2.16.3

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to