crossvm/tools/contrib/memstats_chart

memstats chart

Gather and visualize memory information of each crosvm process, the guest and virtio-balllon for a running crosvm instance.

This tool only supports Linux enviroments.

Usage

Install dependencies

We need to install some Python libraries for visualization.

$ pip install -r ./requirements.txt

Build

Build the tool with cargo and copy the binary to the device if necessary.

$ cd crosvm/tools/contrib/memstats_chart/
$ cargo build --release
# (optional) If crosvm is running on another machine, copy the binary to the machine.
$ scp ./target/release/memstats $DUT:/your/favorite/directory/

If you want to run the binary on aarch64 while your workstation is x86, dev_container is useful.

$ ${CROSVM_PATH}/tools/dev_container
(container)$ cd tools/contrib/memstats_chart
(container)$ cargo build --target aarch64-unknown-linux-gnu
(container)$ cp /scratch/cargo_target/aarch64-unknown-linux-gnu/debug/memstats

Collect data

Run the binary. Note that this tool is assuming that only one crosvm is running on the system. If there are multiple crosvm instances running, this tool will abort.

$ ./memstats --output memory-data.json
# Press Ctrl-C to stop collecting data

Visualize the data

Visualize the obtained JSON file with plot.py.

$ python3 plot.py -i ./memory-data.json
./memory-data.html is written
$ google-chrome ./memory-data.html

How to interpret the graph

crosvm process

The main process's memory usage is divided into the following five sections and shown:

• crosvm (guest disk caches)
• crosvm (guest shared memory)
• crosvm (guest unevictable)
• crosvm (guest used)
• crosvm (host)

These values are computed by the process's RSS and virtio-balloon's statistics.

Other processes

For processes other than the main one, Private_Dirty in /proc/${PID}/smaps is shown. Unlike Pss, Private_Dirty doesn't include the shared memory for the guest physical memory region that the process touched. We use this value because such shared memory regions are counted as a part of the crosvm main process's memory usage.

Balloon

The blue line is the upper bound of the guest's memory usage limited by virtio-balloon.