diff --git a/init.shamu.rc b/init.shamu.rc
index cc6ab48..f9650a3 100644
--- a/init.shamu.rc
+++ b/init.shamu.rc
@@ -148,10 +148,12 @@
     chmod 0660 /sys/devices/platform/msm_serial_hs.0/clock
 
     # update foreground cpuset now that processors are up
-    write /dev/cpuset/foreground/cpus 0-3
+    # reserve CPU 3 for the top app
+    write /dev/cpuset/foreground/cpus 0-2
     write /dev/cpuset/foreground/boost/cpus 0-3
     write /dev/cpuset/background/cpus 0
     write /dev/cpuset/system-background/cpus 0-1
+    write /dev/cpuset/top-app/cpus 0-3
 
     chmod 0660 /dev/ttyHS2
     chown bluetooth net_bt_stack /dev/ttyHS2