This patch gives us the active pending request count which is yet
to be submitted to the GPU.
V2:
* Change 64-bit to atomic for request count. (Tvrtko Ursulin)
V3:
* Remove mutex for request count.
* Rebase.
* Fixes hitting underflow for predictive request. (Tvrtko Ursulin)
V4:
* Rebase.
V5:
* Rebase.
V6:
* Rebase.
V7:
* Rebase.
* Add GEM_BUG_ON for req_cnt.
Cc: Vipin Anand <vipin.an...@intel.com>
Signed-off-by: Ankit Navik <ankit.p.na...@intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
drivers/gpu/drm/i915/gem/i915_gem_context_types.h | 5 +++++
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 ++
drivers/gpu/drm/i915/gt/intel_lrc.c | 9 +++++++++
4 files changed, 17 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 026999b34abd..d0ff999429ff 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -879,6 +879,7 @@ i915_gem_create_context(struct drm_i915_private *i915,
unsigned int flags)
}
trace_i915_context_create(ctx);
+ atomic_set(&ctx->req_cnt, 0);
return ctx;
}
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 28760bd03265..a9ba13f8865e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -171,6 +171,11 @@ struct i915_gem_context {
*/
struct radix_tree_root handles_vma;
+ /** req_cnt: tracks the pending commands, based on which we decide to
+ * go for low/medium/high load configuration of the GPU.
+ */
+ atomic_t req_cnt;
+
/**
* @name: arbitrary name, used for user debug
*
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index d3f4f28e9468..f90c968f95cd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2565,6 +2565,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
if (batch->private)
intel_engine_pool_mark_active(batch->private, eb.request);
+ atomic_inc(&eb.gem_context->req_cnt);
+
trace_i915_request_queue(eb.request, eb.batch_flags);
err = eb_submit(&eb, batch);
err_request:
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c
b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 112531b29f59..ccfebebb0071 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -2143,6 +2143,8 @@ static void execlists_dequeue(struct intel_engine_cs
*engine)
}
if (__i915_request_submit(rq)) {
+ struct i915_gem_context *ctx;
+
if (!merge) {
*port = execlists_schedule_in(last,
port - execlists->pending);
port++;
@@ -2158,6 +2160,13 @@ static void execlists_dequeue(struct intel_engine_cs
*engine)
submit = true;
last = rq;
+
+ ctx = rcu_dereference_protected(
+ rq->context->gem_context, true);
+
+ GEM_BUG_ON(atomic_read(&ctx->req_cnt));
+ if (atomic_read(&ctx->req_cnt) > 0)
+ atomic_dec(&ctx->req_cnt);
}
}
--
2.7.4
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