Set android.display thread to top-app cpusets and schedtune group
android.display being in the foreground cpuset group is an issue. As
seen on M/S, during heavily CPU load it is not given core 3 even though
it might be free and causes jank. This patch adds the thread to the
top-app group to ensure it is placed on all cores during scheduling
decisions.
Doing this required a couple of changes:
- new API to set per-thread cpusets
- changes to DisplayManagerService to set the thread to top-app group
- changes to SystemServer to set the policy toward the end, as doing it
during start of the DisplayManagerService was in issue (issue being
SystemServer calls setSystemProcess.. -> setProcessGroup which overrides
the group settings for threads in the system server process, including
android.display)
Bug: 36631902
Test: Boot and make sure android.display thread is in the top-app group
Change-Id: Icc394ea0ffcf159d11728ad38de114234a29d20f
Signed-off-by: Joel Fernandes <joelaf@google.com>
(cherry picked from commit 474d311cb098e86c078c3f615e1161e2854f1847)
diff --git a/services/core/java/com/android/server/display/DisplayManagerService.java b/services/core/java/com/android/server/display/DisplayManagerService.java
index ddd918f..d83676b 100644
--- a/services/core/java/com/android/server/display/DisplayManagerService.java
+++ b/services/core/java/com/android/server/display/DisplayManagerService.java
@@ -253,6 +253,17 @@
PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
mGlobalDisplayBrightness = pm.getDefaultScreenBrightnessSetting();
+
+ }
+
+ public void setupSchedulerPolicies() {
+ /*
+ * android.display is critical to user experience and we should
+ * make sure it is not in the default foregroup groups, add it to
+ * top-app to make sure it uses all the cores and scheduling
+ * settings for top-app when it runs.
+ */
+ Process.setThreadGroupAndCpuset(DisplayThread.get().getThreadId(), Process.THREAD_GROUP_TOP_APP);
}
@Override