1# memstats chart 2 3Gather and visualize memory information of each crosvm process, the guest and virtio-balllon for a 4running crosvm instance. 5 6This tool only supports Linux enviroments. 7 8 9 10## Usage 11 12## Install dependencies 13 14We need to install some Python libraries for visualization. 15 16```sh 17$ pip install -r ./requirements.txt 18``` 19 20## Build 21 22Build the tool with cargo and copy the binary to the device if necessary. 23 24```sh 25$ cd crosvm/tools/contrib/memstats_chart/ 26$ cargo build --release 27# (optional) If crosvm is running on another machine, copy the binary to the machine. 28$ scp ./target/release/memstats $DUT:/your/favorite/directory/ 29``` 30 31If you want to run the binary on aarch64 while your workstation is x86, `dev_container` is useful. 32 33```sh 34$ ${CROSVM_PATH}/tools/dev_container 35(container)$ cd tools/contrib/memstats_chart 36(container)$ cargo build --target aarch64-unknown-linux-gnu 37(container)$ cp /scratch/cargo_target/aarch64-unknown-linux-gnu/debug/memstats 38``` 39 40### Collect data 41 42Run the binary. Note that this tool is assuming that only one crosvm is running on the system. If 43there are multiple crosvm instances running, this tool will abort. 44 45```sh 46$ ./memstats --output memory-data.json 47# Press Ctrl-C to stop collecting data 48``` 49 50### Visualize the data 51 52Visualize the obtained JSON file with `plot.py`. 53 54```sh 55$ python3 plot.py -i ./memory-data.json 56./memory-data.html is written 57$ google-chrome ./memory-data.html 58``` 59 60#### How to interpret the graph 61 62##### crosvm process 63 64The main process's memory usage is divided into the following five sections and shown: 65 66- crosvm (guest disk caches) 67- crosvm (guest shared memory) 68- crosvm (guest unevictable) 69- crosvm (guest used) 70- crosvm (host) 71 72These values are computed by the process's RSS and virtio-balloon's statistics. 73 74##### Other processes 75 76For processes other than the main one, `Private_Dirty` in `/proc/${PID}/smaps` is shown. Unlike 77`Pss`, `Private_Dirty` doesn't include the shared memory for the guest physical memory region that 78the process touched. We use this value because such shared memory regions are counted as a part of 79the crosvm main process's memory usage. 80 81##### Balloon 82 83The blue line is the upper bound of the guest's memory usage limited by virtio-balloon. 84
