Re: [PATCH] Improve cpupower utility build process description

[Shuah Khan <skhan@linuxfoundation.org>]

On 6/13/24 11:52, Roman Storozhenko wrote:
> Describe more precisely build and install 'make' processes for the default
> and the user defined directories. Show how to run the utility from the
> custom installation directory.
> 
> Signed-off-by: Roman Storozhenko <romeusmeister@gmail.com>
> ---
> Enhance cpupower build process description with the information on
> building and installing the utility to the user defined directories
> as well as with the information on the way of running the utility from
> the custom defined installation directory.

You can move the above into the change log.

> This description is based on my experiments with building the utility
> and each newly described step has been tested.
> ---
>   tools/power/cpupower/README | 133 ++++++++++++++++++++++++++++++++++++++++----
>   1 file changed, 123 insertions(+), 10 deletions(-)
> 
> diff --git a/tools/power/cpupower/README b/tools/power/cpupower/README
> index 1c68f47663b2..ec0d5551ae96 100644
> --- a/tools/power/cpupower/README
> +++ b/tools/power/cpupower/README
> @@ -22,16 +22,129 @@ interfaces [depending on configuration, see below].
>   compilation and installation
>   ----------------------------
>   
> -make
> -su
> -make install
> -
> -should suffice on most systems. It builds libcpupower to put in
> -/usr/lib; cpupower, cpufreq-bench_plot.sh to put in /usr/bin; and
> -cpufreq-bench to put in /usr/sbin. If you want to set up the paths
> -differently and/or want to configure the package to your specific
> -needs, you need to open "Makefile" with an editor of your choice and
> -edit the block marked CONFIGURATION.
> +There are 2 output directories - one for the build output and another for
> +the installation of the build results, that is the utility, library, man pages,

Make sure the lines aren't longer than 75 characters.

> +etc...
> +
> +default directory
> +-----------------
> +
> +In the case of default directory, build and install process requires no
> +additional parameters:
> +
> +build
> +-----
> +
> +The output directory for the 'make' command is the current directory and its
> +subdirs in the kernel tree:
> +tools/power/cpupower
> +
> +$ make
> +
> +install
> +-------
> +
> +'make install' command puts targets to default system dirs:
> +libcpupower to /usr/lib
> +cpupower, cpufreq-bench_plot.sh to /usr/bin
> +cpufreq-bench to /usr/sbin
> +man pages to /usr/man
> +
> +$ sudo make install
> +
> +To put it in other words it makes build results available system-wide, enabling
> +any user to simply start using it without any additional steps

Mention where these are installed.

> +
> +custom directory
> +----------------
> +
> +There are 2 make's command-line variables 'O' and 'DESTDIR' that setup
> +appropriate dirs:
> +'O' - build directory
> +'DESTDIR' - installation directory. This variable could also be setup in
> +the 'CONFIGURATION' block of the "Makefile"
> +
> +build
> +-----
> +
> +$ make O=<your_custom_build_catalog>
> +
> +Example:
> +$ make O=/home/hedin/prj/cpupower/build
> +
> +install
> +-------
> +
> +$ make O=<your_custom_build_catalog> DESTDIR=<your_custom_install_catalog>
> +
> +Example:
> +$ make O=/home/hedin/prj/cpupower/build DESTDIR=/home/hedin/prj/cpupower install
> +
> +Notice that both variables 'O' and 'DESTDIR' have been provided. The reason is
> +that the build results are saved in the custom output dir defined by 'O'
> +variable. So, this dir is the source for the installation step. If only 'DESTDIR'
> +were provided then the 'install' target would assume that the build directory is
> +the current one, build everything there and install from the current dir.
> +
> +
> +clean and uninstall (default directory)
> +---------------------------------------
> +
> +'clean' target is intended for cleanup the build catalog from build results
> +'uninstall' target is intended for removing installed files from the installation
> +catalog
> +
> +default directory
> +-----------------
> +
> +This case is a straightforward one:
> +$ make clean
> +$ make uninstall
> +
> +custom directory
> +----------------
> +
> +Use 'O' command line variable to remove previously built files from the build
> +dir:
> +
> +$ make O=<your_custom_build_catalog> clean
> +
> +Example:
> +$ make O=/home/hedin/prj/cpupower/build clean
> +
> +Use 'DESTDIR' command line variable to uninstall previously installed files from
> +the given dir:
> +
> +$ make DESTDIR=<your_custom_install_catalog>
> +
> +Example:
> +make DESTDIR=/home/hedin/prj/cpupower uninstall
> +
> +
> +running the tool
> +----------------
> +
> +default directory
> +-----------------
> +
> +$ sudo cpupower
> +
> +custom directory
> +----------------
> +
> +When it comes to run the utility from the custom build catalog things become a
> +little bit complicated as 'just run' approach doesn't work.
> +Assuming that the current dir is '<your_custom_install_catalog>/usr', issuing
> +the following command:
> +
> +$ sudo ./bin/cpupower
> +will produce the following error output:
> +./bin/cpupower: error while loading shared libraries: libcpupower.so.1: cannot
> +open shared object file: No such file or directory
> +
> +The issue is that binary cannot find the 'libcpupower' library. So, we shall
> +point to the lib dir:
> +sudo LD_LIBRARY_PATH=lib64/ ./bin/cpupower

Nice. This is a good tip worth adding to the document.

>   
>   
>   THANKS

What is this line?

> 
> ---
> base-commit: 6906a84c482f098d31486df8dc98cead21cce2d0
> change-id: 20240613-fix-cpupower-doc-9f9365d15c16
> 
> Best regards,

I think your patch and email got munged. Please use git-send email
to send the patch.

thanks,
-- Shuah