This repo (https://github.com/awslabs/damo) was one of the official GitHub repos for damo. However, after 2024-09-05, this has been[1] no longer the official GitHub repo. Please use the new official GitHub repo (https://github.com/damonitor/damo) or the kernel.org repo (https://git.kernel.org/pub/scm/linux/kernel/git/sj/damo.git/) instead.
[1] https://lore.kernel.org/[email protected]
damo is a user space tool for DAMON. Using
this, you can monitor the data access patterns of your system or workloads and
make data access-aware memory management optimizations.
Official git repos for damo are hosted on kernel.org and GitHub:
- kernel.org: https://git.kernel.org/pub/scm/linux/kernel/git/sj/damo.git
- GitHub: https://github.com/damonitor/damo
Note that the repo under awslabs GitHub organization (https://github.com/awslabs/damo) was used as the official repo before. It will be no more official repo that maintained by DAMON maintainer after 2024-09-05.
Please click the below thumbnail to show the short demo video.
Follow below instructions and commands to monitor and visualize the access pattern of your workload.
$ # ensure DAMON is enabled on your kernel
$ # install damo using packaging systems listed above,
$ # or cloning the source repo and updating $PATH.
$ sudo damo start $(pidof <your workload>)
$ sudo damo show
$ sudo damo record ongoing
$ sudo damo report heats --heatmap stdout --stdout_heatmap_color emotion
The second and last commands will show the access pattern of your workload, like below:
Please refer to 'Install' section of the project webpage.
The below sections provide quick introductions for damo's major features.
For more detailed usage, please refer to USAGE.md file.
Nothing at all but indicate which version is more fresh. A higher version number means it is more recently released.
It will install the latest stable version of damo. If you want, you can
also install less stable but more fresh damo from source code. For that,
fetch the next branch of the source tree and use damo executable file in
the tree.
$ git clone https://github.com/damonitor/damo -b next
Please refer to CONTRIBUTING file.
Why some features are not documented on USAGE.md file?
Because those are not yet stabilized. In other words, such features are in their experimental stages, and therefore could be deprecated and removed without notice and grace periods. The documented features could also be deprecated, but those will provide some notifications and grace periods. If there are some features you're relying on but not documented, please report your usecase to the community.
The list of features that will be, or already deprecated, the deprecation schedule, and their alternatives are summarized in FEATURES_DEPRECATION_SCHEDULE.md file.
Below are quick introductions for damo's major features.
For more detailed usage, please refer to USAGE.md file.
Below commands repeatedly get a snapshot of the access pattern of a program for every second.
$ git clone https://github.com/sjp38/masim
$ cd masim; make; ./masim ./configs/zigzag.cfg --silent &
$ sudo damo start --target_pid $(pidof masim)
$ while :; do sudo damo show; sleep 1; done
The first two lines of the commands get an artificial memory access generator program and run it in the background. It will repeatedly access two 100 MiB-sized memory regions one by one. You can substitute this with your real workload.
The third line asks damo to start monitoring the access pattern of the
process. Finally, the last line retries a snapshot of the monitoring results
every second and show on terminal.
Below commands record memory access patterns of a program and save the
monitoring results in damon.data file.
$ git clone https://github.com/sjp38/masim
$ cd masim; make; ./masim ./configs/zigzag.cfg --silent &
$ sudo damo record -o damon.data $(pidof masim)
The first two lines of the commands get an artificial memory access generator
program and run it in the background. It will repeatedly access two 100
MiB-sized memory regions one by one. You can substitute this with your real
workload. The last line asks damo to record the access pattern in
damon.data file.
Below three commands visualize the recorded access patterns into three image files.
$ damo report heats --heatmap stdout
$ damo report wss --range 0 101 1
$ damo report wss --range 0 101 1 --sortby time --plot
access_pattern_heatmap.pngwill show the data access pattern in a heatmap, which shows when (x-axis) what memory region (y-axis) is how frequently accessed (color).wss_dist.pngwill show the distribution of the working set size.wss_chron_change.pngwill show how the working set size has chronologically changed.
You can show the images on a web page [1]. Those made with other realistic workloads are also available [2,3,4].
[1] https://damonitor.github.io/doc/html/latest/admin-guide/mm/damon/start.html#visualizing-recorded-patterns
[2] https://damonitor.github.io/test/result/visual/latest/rec.heatmap.1.png.html
[3] https://damonitor.github.io/test/result/visual/latest/rec.wss_sz.png.html
[4] https://damonitor.github.io/test/result/visual/latest/rec.wss_time.png.html
Below command makes every memory region of size >=4K that hasn't accessed for
=60 seconds in your workload to be swapped out. By doing this, you can make your workload more memory efficient with only modest performance overhead.
$ sudo damo start --damos_access_rate 0 0 --damos_sz_region 4K max \
--damos_age 60s max --damos_action pageout \
<pid of your workload>
You can also show access pattern heatmap, memory footprints, and hotspot functions of the system and/or workloads all at once in live, like below.
