1*bb4ee6a4SAndroid Build Coastguard Worker# Balloon 2*bb4ee6a4SAndroid Build Coastguard Worker 3*bb4ee6a4SAndroid Build Coastguard Workercrosvm supports 4*bb4ee6a4SAndroid Build Coastguard Worker[virtio-balloon](https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html#x1-2790005) 5*bb4ee6a4SAndroid Build Coastguard Workerfor managing guest memory. 6*bb4ee6a4SAndroid Build Coastguard Worker 7*bb4ee6a4SAndroid Build Coastguard Worker## How to control the balloon size 8*bb4ee6a4SAndroid Build Coastguard Worker 9*bb4ee6a4SAndroid Build Coastguard WorkerWhen running a VM, specify `VM_SOCKET` with `-s` option. (example: `/run/crosvm.sock`) 10*bb4ee6a4SAndroid Build Coastguard Worker 11*bb4ee6a4SAndroid Build Coastguard Worker```sh 12*bb4ee6a4SAndroid Build Coastguard Workercrosvm run \ 13*bb4ee6a4SAndroid Build Coastguard Worker -s ${CROSVM_SOCKET} \ 14*bb4ee6a4SAndroid Build Coastguard Worker # usual crosvm args 15*bb4ee6a4SAndroid Build Coastguard Worker /path/to/bzImage 16*bb4ee6a4SAndroid Build Coastguard Worker``` 17*bb4ee6a4SAndroid Build Coastguard Worker 18*bb4ee6a4SAndroid Build Coastguard WorkerThen, open another terminal and specify the balloon size in bytes with `crosvm balloon` command. 19*bb4ee6a4SAndroid Build Coastguard Worker 20*bb4ee6a4SAndroid Build Coastguard Worker```sh 21*bb4ee6a4SAndroid Build Coastguard Workercrosvm balloon 4096 ${CROSVM_SOCKET} 22*bb4ee6a4SAndroid Build Coastguard Worker``` 23*bb4ee6a4SAndroid Build Coastguard Worker 24*bb4ee6a4SAndroid Build Coastguard WorkerNote: The size of balloon is managed in 4096 bytes units. The specified value will be rounded down 25*bb4ee6a4SAndroid Build Coastguard Workerto a multiple of 4096 bytes. 26*bb4ee6a4SAndroid Build Coastguard Worker 27*bb4ee6a4SAndroid Build Coastguard WorkerYou can confirm the balloon size with `crosvm balloon_stats` command. 28*bb4ee6a4SAndroid Build Coastguard Worker 29*bb4ee6a4SAndroid Build Coastguard Worker```sh 30*bb4ee6a4SAndroid Build Coastguard Workercrosvm balloon_stats ${CROSVM_SOCKET} 31*bb4ee6a4SAndroid Build Coastguard Worker``` 32