Add GPU.Scheduler.RunTaskTime histogram

The histogram records the wall time for each GPU task. This will
eventually be used to add a slow report trigger to capture traces for
long running tasks from canary.

Bug: 1064662
Change-Id: I30ec4a7f583fc197f916a55eae7dd3b1fbf57bf4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144340Reviewed-by: Etienne Bergeron <etienneb@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759239}

gpu/command_buffer/service/scheduler.cc

@@ -8,8 +8,10 @@
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
+#include "base/timer/elapsed_timer.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/traced_value.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
@@ -518,6 +520,7 @@ void Scheduler::RunNextTask() {
   scheduling_queue_.pop_back();
 
   TRACE_EVENT1("gpu", "Scheduler::RunNextTask", "state", state.AsValue());
+  base::ElapsedTimer task_timer;
 
   Sequence* sequence = GetSequence(state.sequence_id);
   DCHECK(sequence);
@@ -567,6 +570,11 @@ void Scheduler::RunNextTask() {
     }
   }
 
+  UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES(
+      "GPU.Scheduler.RunTaskTime", task_timer.Elapsed(),
+      base::TimeDelta::FromMicroseconds(10), base::TimeDelta::FromSeconds(30),
+      100);
+
   task_runner_->PostTask(FROM_HERE,
                          base::BindOnce(&Scheduler::RunNextTask, weak_ptr_));
 }

tools/metrics/histograms/histograms.xml

@@ -61882,6 +61882,18 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="GPU.Scheduler.RunTaskTime" units="microseconds"
+    expires_after="2020-12-31">
+  <owner>kylechar@chromium.org</owner>
+  <owner>chrome-gpu-metrics@google.com</owner>
+  <summary>
+    Records the wall time taken for each GPU scheduler task to run. The time
+    delta starts when the GPU scheduler pops the task off the task queue and
+    finishes when the task has completed. Only recorded for clients with high
+    resolution clocks.
+  </summary>
+</histogram>
+
 <histogram name="GPU.setIsAcceleratedCompositingActive"
     enum="GPUsetIsAcceleratedCompositingActive" expires_after="M85">
   <owner>vmiura@chromium.org</owner>