kw - Inglorious kernel developer workflow tool

kw - Inglorious kernel developer workflow tool#

Author:

Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>

Author:

Matheus Tavares <matheus.bernardino@usp.br>

Date:

2018-05-18

Copyright:

GPLv2+

Manual section:

1

Manual group:

Kernel Workflow

SYNOPSIS#

kw <command> [<option> …]

DESCRIPTION#

kw mission is: reduce the overhead related with infrastructure project setup in projects that have a similar workflow to the Linux Kernel. It can (and should) be customized by editing its various configuration files (preferably through the kw config command).

COMMANDS#

kw offers several subcommands catering to different audiences and targeting different functionality groups. Most subcommands have sane defaults.

COMMANDS FOR DEPLOY NEW KERNEL IMAGE AND MODULE#

When we develop for Linux Kernel, we continuously want to install or update the current version of the Kernel image or modules, and these tasks may require several steps to be accomplished. For this reason, kw provides a command named deploy that attempts to handle all the complexity related to the new Kernel installation. It is essential to highlight that we try to support two different types of deploy: local and remote. When you want to update your host machine, you can use the local option. Also, we provide the remote option, which is much more flexible since it uses network; notice that this approach is the most generic one because you can use it for vm and local.

COMMANDS FOR WORKING WITH CODE#

Projects that have a similar workflow to the Linux Kernel usually have a set of tools that simplify part of the tasks related with the code. This section describes some of the key features supported by kw to help with code.

SUBSYSTEM COMMANDS#

Linux kernel has multiple subsystems that expose operations via sysfs or provide mechanisms for userspace to interact with the driver. For this reason, kw offers some options that target some specific subsystems for providing facilities for users to interact with a particular subsystem. Currently, we only support drm.

COMMAND TO DEBUG THE LINUX KERNEL#

Linux kernel provides multiple mechanisms for debugging; in particular, kw tries to simplify the debug process for three of them: events, ftrace, and dmesg. All the debug options are intended to support remote and local targets.

COMMAND TO INTERACT WITH THE PUBLIC MAILING LISTS#

Some projects, like the Linux kernel, are collaboratively developed using public mailing lists. kw has a feature that provides a friendly UI to these lists and integrates other kw features to allow a unified kernel development with a focus on patch-reviewing.

OTHER COMMANDS#

This section describes a tool available in kw to help developers keep track of configuration files and other features provided by kw that do not fit in the previous sections.

clear-cache#

Clean all files generated by kw.

h, help#

Show basic help.

version, --version, -v#

Show kworkflow version.

EXAMPLES#

For these examples, we assume that the relevant fields in your configuration files (located by default in .kw/) have already been setup. We recommend the use of kw config for managing your local and global configurations.

First, if you are working in a specific kernel module, and if you want to install your recent changes in your local machine you can use:

cd <kernel-path>
kw d --local --modules

For building and installing a new module version based on the current kernel version, you can use:

cd <kernel-path>
kw bd

For checking the code style:

cd <kernel-path>
kw c drivers/iio/dummy/
kw c drivers/iio/dummy/iio_simple_dummy.c

If you want to check the maintainers:

cd <kernel-path>
kw m drivers/iio/dummy/iio_simple_dummy.c

In case you want that kw saves your current .config file, you can use:

cd <kernel-path>
kw k --save my_current_config

You can see the config’s file maintained by kw with:

kw k --list

You can turn on your VM with:

kw u

After you start your VM you can ssh into it with:

kw s -c="dmesg -wH"
kw s

You can see data related to your kw usage by using the --statistics flag on the report option, see some examples below:

kw report --statistics --day
kw report --statistics --week
kw report --statistics --month
kw report --statistics --year

You can also request a specific day, week, month, or year. For example:

kw report --statistics --day=2020/05/12
kw report --statistics --week=2020/02/29
kw report --statistics --month=2020/04
kw report --statistics --year=1984

If you are working with DRM drivers, you can take advantage of load and unload commands combined with GUI control commands. For example:

kw drm --load-module='amdgpu' --gui-on # Load a driver and trigger the user GUI
kw drm --unload-module='amdgpu' # Turn off user GUI and unload the driver

If you need to debug an issue based on event values, you can try the debug options. For example:

kw debug --list # Show all events debug available in the target
kw debug --list --event="amdgpu_dm" # Show all events available under amdgpu_dm
kw debug --event='amdgpu_dm:amdgpu_dm_dce_clocks_state[sclk_khz > 0]' # Enable amdgpu_dm_dce_clocks_state event and filter by sclk_khz > 0
kw debug --disable --event='amdgpu_dm:amdgpu_dm_dce_clocks_state' # Disable amdgpu_dm_dce_clocks_state events
kw debug --event='amdgpu_dm:amdgpu_dm_dce_clocks_state' --history # Save each debug in a separated set of files
kw debug --event='amdgpu_dm:amdgpu_dm_dce_clocks_state' --follow # Wait for new event message
kw debug --event='amdgpu_dm:amdgpu_dm_dce_clocks_state' --cmd="export DISPLAY=:0.0 && xrandr --props" # Enable amdgpu_dm_dce_clocks_state, run "export DISPLAY=:0.0 && xrandr --props", collect logs, and disable events

Note

You have to wait for the sshd to become ready.