[Intel-gfx] [RFC 06/10] drm/i915: Track runtime spent in closed GEM contexts

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

As GEM contexts are closed we want to have the DRM client remember how
much GPU time they used (per class) so later we can used it for smarter
purposes.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 +++++++++++-
 drivers/gpu/drm/i915/i915_drm_client.h      |  7 +++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index c521155a6474..36dc577a23c4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -316,8 +316,18 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 
 	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
 
-	if (client)
+	if (client) {
+		unsigned int i;
+
+		/* Transfer accumulated runtime to the parent drm client. */
+		BUILD_BUG_ON(ARRAY_SIZE(client->past_runtime) !=
+			     ARRAY_SIZE(ctx->past_runtime));
+		for (i = 0; i < ARRAY_SIZE(client->past_runtime); i++)
+			atomic64_add(atomic64_read(&ctx->past_runtime[i]),
+				     &client->past_runtime[i]);
+
 		i915_drm_client_put(client);
+	}
 
 	spin_lock(&ctx->i915->gem.contexts.lock);
 	list_del(&ctx->link);
diff --git a/drivers/gpu/drm/i915/i915_drm_client.h b/drivers/gpu/drm/i915/i915_drm_client.h
index b56a271737ff..72e66027e0f1 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.h
+++ b/drivers/gpu/drm/i915/i915_drm_client.h
@@ -16,6 +16,8 @@
 #include <linux/sched.h>
 #include <linux/xarray.h>
 
+#include "gt/intel_engine_types.h"
+
 struct i915_drm_clients {
 	struct xarray xarray;
 	u32 next_id;
@@ -42,6 +44,11 @@ struct i915_drm_client {
 		struct device_attribute pid;
 		struct device_attribute name;
 	} attr;
+
+	/**
+	 * @past_runtime: Accumulation of pphwsp runtimes from closed contexts.
+	 */
+	atomic64_t past_runtime[MAX_ENGINE_CLASS + 1];
 };
 
 void i915_drm_clients_init(struct i915_drm_clients *clients);
-- 
2.20.1