From 392db573b35d6fe09c4da094ed81c54ed528a511 Mon Sep 17 00:00:00 2001
From: Tim Murray <timmurray@google.com>
Date: Tue, 10 Nov 2015 14:29:45 -0800
Subject: [PATCH] Set cpuset from surfaceflinger.

SurfaceFlinger shouldn't be limited to little cores exclusively, as the
binder threads should be placed on big cores when they are in the
critical path for a RenderThread.

bug 25745866

Change-Id: I9fb65f6d951733f91b4735ff27018411b58b2bfb
---
 services/surfaceflinger/Android.mk              | 4 ++++
 services/surfaceflinger/main_surfaceflinger.cpp | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 1eb23616c..1901ef982 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -122,6 +122,10 @@ LOCAL_LDFLAGS := -Wl,--version-script,art/sigchainlib/version-script.txt -Wl,--e
 LOCAL_CFLAGS := -DLOG_TAG=\"SurfaceFlinger\"
 LOCAL_CPPFLAGS := -std=c++11
 
+ifneq ($(ENABLE_CPUSETS),)
+    LOCAL_CFLAGS += -DENABLE_CPUSETS
+endif
+
 LOCAL_SRC_FILES := \
     main_surfaceflinger.cpp
 
diff --git a/services/surfaceflinger/main_surfaceflinger.cpp b/services/surfaceflinger/main_surfaceflinger.cpp
index a74bc4cd9..6fa8b5317 100644
--- a/services/surfaceflinger/main_surfaceflinger.cpp
+++ b/services/surfaceflinger/main_surfaceflinger.cpp
@@ -41,6 +41,13 @@ int main(int, char**) {
 
     set_sched_policy(0, SP_FOREGROUND);
 
+#ifdef ENABLE_CPUSETS
+    // Put most SurfaceFlinger threads in the system-background cpuset
+    // Keeps us from unnecessarily using big cores
+    // Do this after the binder thread pool init
+    set_cpuset_policy(0, SP_SYSTEM);
+#endif
+
     // initialize before clients can connect
     flinger->init();