mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
114 lines
4.4 KiB
114 lines
4.4 KiB
.. SPDX-License-Identifier: GPL-2.0 |
|
|
|
=============== |
|
Getting Started |
|
=============== |
|
|
|
This document briefly describes how you can use DAMON by demonstrating its |
|
default user space tool. Please note that this document describes only a part |
|
of its features for brevity. Please refer to :doc:`usage` for more details. |
|
|
|
|
|
TL; DR |
|
====== |
|
|
|
Follow the commands below to monitor and visualize the memory access pattern of |
|
your workload. :: |
|
|
|
# # build the kernel with CONFIG_DAMON_*=y, install it, and reboot |
|
# mount -t debugfs none /sys/kernel/debug/ |
|
# git clone https://github.com/awslabs/damo |
|
# ./damo/damo record $(pidof <your workload>) |
|
# ./damo/damo report heat --plot_ascii |
|
|
|
The final command draws the access heatmap of ``<your workload>``. The heatmap |
|
shows which memory region (x-axis) is accessed when (y-axis) and how frequently |
|
(number; the higher the more accesses have been observed). :: |
|
|
|
111111111111111111111111111111111111111111111111111111110000 |
|
111121111111111111111111111111211111111111111111111111110000 |
|
000000000000000000000000000000000000000000000000001555552000 |
|
000000000000000000000000000000000000000000000222223555552000 |
|
000000000000000000000000000000000000000011111677775000000000 |
|
000000000000000000000000000000000000000488888000000000000000 |
|
000000000000000000000000000000000177888400000000000000000000 |
|
000000000000000000000000000046666522222100000000000000000000 |
|
000000000000000000000014444344444300000000000000000000000000 |
|
000000000000000002222245555510000000000000000000000000000000 |
|
# access_frequency: 0 1 2 3 4 5 6 7 8 9 |
|
# x-axis: space (140286319947776-140286426374096: 101.496 MiB) |
|
# y-axis: time (605442256436361-605479951866441: 37.695430s) |
|
# resolution: 60x10 (1.692 MiB and 3.770s for each character) |
|
|
|
|
|
Prerequisites |
|
============= |
|
|
|
Kernel |
|
------ |
|
|
|
You should first ensure your system is running on a kernel built with |
|
``CONFIG_DAMON_*=y``. |
|
|
|
|
|
User Space Tool |
|
--------------- |
|
|
|
For the demonstration, we will use the default user space tool for DAMON, |
|
called DAMON Operator (DAMO). It is available at |
|
https://github.com/awslabs/damo. The examples below assume that ``damo`` is on |
|
your ``$PATH``. It's not mandatory, though. |
|
|
|
Because DAMO is using the debugfs interface (refer to :doc:`usage` for the |
|
detail) of DAMON, you should ensure debugfs is mounted. Mount it manually as |
|
below:: |
|
|
|
# mount -t debugfs none /sys/kernel/debug/ |
|
|
|
or append the following line to your ``/etc/fstab`` file so that your system |
|
can automatically mount debugfs upon booting:: |
|
|
|
debugfs /sys/kernel/debug debugfs defaults 0 0 |
|
|
|
|
|
Recording Data Access Patterns |
|
============================== |
|
|
|
The commands below record the memory access patterns of a program and save the |
|
monitoring results to a file. :: |
|
|
|
$ git clone https://github.com/sjp38/masim |
|
$ cd masim; make; ./masim ./configs/zigzag.cfg & |
|
$ sudo damo record -o damon.data $(pidof masim) |
|
|
|
The first two lines of the commands download an artificial memory access |
|
generator program and run it in the background. The generator 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 the ``damon.data`` file. |
|
|
|
|
|
Visualizing Recorded Patterns |
|
============================= |
|
|
|
The following three commands visualize the recorded access patterns and save |
|
the results as separate image files. :: |
|
|
|
$ damo report heats --heatmap access_pattern_heatmap.png |
|
$ damo report wss --range 0 101 1 --plot wss_dist.png |
|
$ damo report wss --range 0 101 1 --sortby time --plot wss_chron_change.png |
|
|
|
- ``access_pattern_heatmap.png`` will visualize the data access pattern in a |
|
heatmap, showing which memory region (y-axis) got accessed when (x-axis) |
|
and how frequently (color). |
|
- ``wss_dist.png`` will show the distribution of the working set size. |
|
- ``wss_chron_change.png`` will show how the working set size has |
|
chronologically changed. |
|
|
|
You can view the visualizations of this example workload at [1]_. |
|
Visualizations of other realistic workloads are available at [2]_ [3]_ [4]_. |
|
|
|
.. [1] https://damonitor.github.io/doc/html/v17/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
|
|
|