Widen CPU affinity set. (#53136)

For devices with 1 fast core, the current affinity set is less idea because it forces UI and raster on the same thread. Widen this to exclude slow cores instead of including only the fast core.

Author: jonahwilliams

fml/cpu_affinity.cc

@@ -58,6 +58,8 @@ CPUSpeedTracker::CPUSpeedTracker(std::vector<CpuIndexAndSpeed> data)
     }
     if (data.speed == min_speed_value) {
       efficiency_.push_back(data.index);
+    } else {
+      not_efficiency_.push_back(data.index);
     }
   }
 
@@ -77,6 +79,8 @@ const std::vector<size_t>& CPUSpeedTracker::GetIndices(
       return efficiency_;
     case CpuAffinity::kNotPerformance:
       return not_performance_;
+    case CpuAffinity::kNotEfficiency:
+      return not_efficiency_;
   }
 }
 

fml/cpu_affinity.h

@@ -26,6 +26,9 @@ enum class CpuAffinity {
 
   /// @brief Request affinity for all non-performance cores.
   kNotPerformance,
+
+  /// @brief Request affinity for all non-efficiency cores.
+  kNotEfficiency,
 };
 
 /// @brief Request count of efficiency cores.
@@ -79,6 +82,7 @@ class CPUSpeedTracker {
   std::vector<size_t> efficiency_;
   std::vector<size_t> performance_;
   std::vector<size_t> not_performance_;
+  std::vector<size_t> not_efficiency_;
 };
 
 /// @note Visible for testing.

fml/cpu_affinity_unittests.cc

@@ -29,6 +29,9 @@ TEST(CpuAffinity, NormalSlowMedFastCores) {
   ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotPerformance).size(), 2u);
   ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotPerformance)[0], 0u);
   ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotPerformance)[1], 1u);
+  ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotEfficiency).size(), 2u);
+  ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotEfficiency)[0], 1u);
+  ASSERT_EQ(tracker.GetIndices(CpuAffinity::kNotEfficiency)[1], 2u);
 }
 
 TEST(CpuAffinity, NoCpuData) {

shell/platform/android/android_shell_holder.cc

@@ -49,14 +49,14 @@ static void AndroidPlatformThreadConfigSetter(
       break;
     }
     case fml::Thread::ThreadPriority::kDisplay: {
-      fml::RequestAffinity(fml::CpuAffinity::kPerformance);
+      fml::RequestAffinity(fml::CpuAffinity::kNotEfficiency);
       if (::setpriority(PRIO_PROCESS, 0, -1) != 0) {
         FML_LOG(ERROR) << "Failed to set UI task runner priority";
       }
       break;
     }
     case fml::Thread::ThreadPriority::kRaster: {
-      fml::RequestAffinity(fml::CpuAffinity::kPerformance);
+      fml::RequestAffinity(fml::CpuAffinity::kNotEfficiency);
       // Android describes -8 as "most important display threads, for
       // compositing the screen and retrieving input events". Conservatively
       // set the raster thread to slightly lower priority than it.