From 9e41c7479ccaedb89a89a58079570ca0ee0e3727 Mon Sep 17 00:00:00 2001
From: Tim Murray <timmurray@google.com>
Date: Mon, 8 Jun 2015 14:56:53 -0700
Subject: [PATCH] add cpuset support

This moves ActivityManager from using fg/bg cgroups to fg/bg cpusets,
which improves load balancing on appropriate devices.

bug 21782794

Change-Id: Ife149ea551b8b3611a826566b8c8fc8573fdf654
---
 core/jni/Android.mk               |  4 ++++
 core/jni/android_util_Process.cpp | 25 ++++++++++++++++++++++---
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index faf926cc53728..5e5450e953719 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -16,6 +16,10 @@ else
     LOCAL_CFLAGS += -DPACKED=""
 endif
 
+ifneq ($(ENABLE_CPUSETS),)
+    LOCAL_CFLAGS += -DENABLE_CPUSETS
+endif
+
 LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES -DEGL_EGLEXT_PROTOTYPES
 
 LOCAL_CFLAGS += -DU_USING_ICU_NAMESPACE=0
diff --git a/core/jni/android_util_Process.cpp b/core/jni/android_util_Process.cpp
index 28307249249fc..ee8fb195002d3 100644
--- a/core/jni/android_util_Process.cpp
+++ b/core/jni/android_util_Process.cpp
@@ -239,7 +239,8 @@ void android_os_Process_setProcessGroup(JNIEnv* env, jobject clazz, int pid, jin
         if (t_pri <= ANDROID_PRIORITY_AUDIO) {
             int scheduler = sched_getscheduler(t_pid);
             if ((scheduler == SCHED_FIFO) || (scheduler == SCHED_RR)) {
-                // This task wants to stay in it's current audio group so it can keep it's budget
+                // This task wants to stay in its current audio group so it can keep its budget
+                // don't update its cpuset or cgroup
                 continue;
             }
         }
@@ -247,15 +248,33 @@ void android_os_Process_setProcessGroup(JNIEnv* env, jobject clazz, int pid, jin
         if (isDefault) {
             if (t_pri >= ANDROID_PRIORITY_BACKGROUND) {
                 // This task wants to stay at background
+                // update its cpuset so it doesn't only run on bg core(s)
+#ifdef ENABLE_CPUSETS
+                int err = set_cpuset_policy(t_pid, sp);
+                if (err != NO_ERROR) {
+                    signalExceptionForGroupError(env, -err);
+                    break;
+                }
+#endif
                 continue;
             }
         }
-
-        int err = set_sched_policy(t_pid, sp);
+        int err;
+#ifdef ENABLE_CPUSETS
+        // set both cpuset and cgroup for general threads
+        err = set_cpuset_policy(t_pid, sp);
         if (err != NO_ERROR) {
             signalExceptionForGroupError(env, -err);
             break;
         }
+#endif
+
+        err = set_sched_policy(t_pid, sp);
+        if (err != NO_ERROR) {
+            signalExceptionForGroupError(env, -err);
+            break;
+        }
+
     }
     closedir(d);
 }