Add a system property to init that drops caches.
* Users can't call /proc/sys/vm/drop_caches otherwise.
* Requires change with associated SELinux permissions.
Bug: 178647679
Test: flashed user build and dropped caches; no avc denials.
Test: flashed userdebug build and dropped caches w/o root.
Change-Id: Ibc91991509f0902d1c04c958fefc0966233f0b2e
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 05da3da..ce2dd9e 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -1141,6 +1141,11 @@
on property:sys.sysctl.extra_free_kbytes=*
write /proc/sys/vm/extra_free_kbytes ${sys.sysctl.extra_free_kbytes}
+# Allow users to drop caches
+on property:perf.drop_caches=3
+ write /proc/sys/vm/drop_caches 3
+ setprop perf.drop_caches 0
+
# "tcp_default_init_rwnd" Is too long!
on property:net.tcp_def_init_rwnd=*
write /proc/sys/net/ipv4/tcp_default_init_rwnd ${net.tcp_def_init_rwnd}