I tried to run Dalvik in portable mode by setting /data/local.prop as follows:
dalvik.vm.execution-mode = int:portable
But after I reboot the device (which is a Nexus 7), app_process (hosting zygote) still starts in jit mode.
However, if I run:
adb shell stop
adb shell setprop dalvik.vm.execution-mode int:portable
adb shell start
Then app_process will run in portable mode. Is /data/local.prop deprecated or something is missing here?