Merge "mm_events: Add knob to remove mm_event tracing instance" into sc-dev
diff --git a/cmds/atrace/atrace.rc b/cmds/atrace/atrace.rc
index 37fc9a9..e3c4ede 100644
--- a/cmds/atrace/atrace.rc
+++ b/cmds/atrace/atrace.rc
@@ -266,7 +266,10 @@
chmod 0666 /sys/kernel/debug/tracing/per_cpu/cpu15/trace
chmod 0666 /sys/kernel/tracing/per_cpu/cpu15/trace
-on post-fs-data
+# Only create the tracing instance if persist.mm_events.enabled
+# Attempting to remove the tracing instance after it has been created
+# will likely fail with EBUSY as it would be in use by traced_probes.
+on post-fs-data && property:persist.mm_events.enabled=true
# Create MM Events Tracing Instance for Kmem Activity Trigger
mkdir /sys/kernel/debug/tracing/instances/mm_events 0755 system system
mkdir /sys/kernel/tracing/instances/mm_events 0755 system system
@@ -275,10 +278,18 @@
chmod 0666 /sys/kernel/debug/tracing/instances/mm_events/buffer_size_kb
chmod 0666 /sys/kernel/tracing/instances/mm_events/buffer_size_kb
+# Set the default buffer size to the minimum
+ write /sys/kernel/debug/tracing/instances/mm_events/buffer_size_kb 1
+ write /sys/kernel/tracing/instances/mm_events/buffer_size_kb 1
+
# Read and enable tracing
chmod 0666 /sys/kernel/debug/tracing/instances/mm_events/tracing_on
chmod 0666 /sys/kernel/tracing/instances/mm_events/tracing_on
+# Tracing disabled by default
+ write /sys/kernel/debug/tracing/instances/mm_events/tracing_on 0
+ write /sys/kernel/tracing/instances/mm_events/tracing_on 0
+
# Read and truncate kernel trace
chmod 0666 /sys/kernel/debug/tracing/instances/mm_events/trace
chmod 0666 /sys/kernel/tracing/instances/mm_events/trace