[4/9] drm/i915: Track runtime spent in unreachable intel_contexts

Commit Message

Tvrtko Ursulin Sept. 4, 2020, 12:59 p.m. UTC

From: Tvrtko Ursulin <[e-mail]>

As contexts are abandoned we want to remember how much GPU time they used
(per class) so later we can used it for smarter purposes.

Signed-off-by: Tvrtko Ursulin <[e-mail]>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c       | 13 ++++++++++++-
 drivers/gpu/drm/i915/gem/i915_gem_context_types.h |  5 +++++
 2 files changed, 17 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index ab8d25eda204..05f3a6fd9be4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -253,7 +253,19 @@  static void free_engines_rcu(struct rcu_head *rcu)
 {
 	struct i915_gem_engines *engines =
 		container_of(rcu, struct i915_gem_engines, rcu);
+	struct i915_gem_context *ctx = engines->ctx;
+	struct i915_gem_engines_iter it;
+	struct intel_context *ce;
+
+	/* Transfer accumulated runtime to the parent GEM context. */
+	for_each_gem_engine(ce, engines, it) {
+		unsigned int class = ce->engine->uabi_class;
 
+		GEM_BUG_ON(class >= ARRAY_SIZE(ctx->past_runtime));
+		atomic64_add(ce->runtime.total, &ctx->past_runtime[class]);
+	}
+
+	i915_gem_context_put(ctx);
 	i915_sw_fence_fini(&engines->fence);
 	free_engines(engines);
 }
@@ -274,7 +286,6 @@  engines_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 			list_del(&engines->link);
 			spin_unlock_irqrestore(&ctx->stale.lock, flags);
 		}
-		i915_gem_context_put(engines->ctx);
 		break;
 
 	case FENCE_FREE:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
index 31a6a30f7ea8..e473984b52c8 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -178,6 +178,11 @@  struct i915_gem_context {
 		spinlock_t lock;
 		struct list_head engines;
 	} stale;
+
+	/**
+	 * @past_runtime: Accumulation of freed intel_context pphwsp runtimes.
+	 */
+	atomic64_t past_runtime[MAX_ENGINE_CLASS + 1];
 };
 
 #endif /* __I915_GEM_CONTEXT_TYPES_H__ */