Document using libmemunreachable on an app
Document dumpsys meminfo --unreachable, and how to enable
malloc_debug backtraces on a single app.
Test: none
Change-Id: I649afdfff1c7438f74950395639b06c39cae3ca0
diff --git a/libmemunreachable/README.md b/libmemunreachable/README.md
index ae8fa94..6d9141a 100644
--- a/libmemunreachable/README.md
+++ b/libmemunreachable/README.md
@@ -12,6 +12,27 @@
Usage
-------
+### In Android apps ###
+
+libmemunreachble is loaded by zygote and can be triggered with `dumpsys -t 600 meminfo --unreachable [process]`.
+
+To enable malloc\_debug backtraces on allocations for a single app process on a userdebug device, use:
+```
+adb root
+adb shell setprop libc.debug.malloc.program app_process
+adb shell setprop wrap.[process] "\$\@"
+adb shell setprop libc.debug.malloc.options backtrace=4
+```
+
+Kill and restart the app, trigger the leak, and then run `dumpsys -t 600 meminfo --unreachable [process]`.
+
+To disable malloc\_debug:
+```
+adb shell setprop libc.debug.malloc.options "''"
+adb shell setprop libc.debug.malloc.program "''"
+adb shell setprop wrap.[process] "''"
+```
+
### C interface ###
#### `bool LogUnreachableMemory(bool log_contents, size_t limit)` ####
