Re: [PATCH V8 00/14] RTLA: An interface for osnoise/timerlat tracers

[Tao Zhou <tao.zhou@linux.dev>]

On Mon, Nov 29, 2021 at 12:07:38PM +0100, Daniel Bristot de Oliveira wrote:

> The rtla(1) is a meta-tool that includes a set of commands that
> aims to analyze the real-time properties of Linux. But instead of
> testing Linux as a black box, rtla leverages kernel tracing
> capabilities to provide precise information about the properties
> and root causes of unexpected results.
> 
> To start, it presents an interface to the osnoise and timerlat tracers.
> In the future, it will also serve as home to the rtsl [1] and other
> latency/noise tracers.
> 
> If you just want to run it, you can download the tarball here:
>   - https://bristot.me/files/rtla/tarball/rtla-0.4.tar.bz2
> 
> To compile rtla on fedora you need:
>   $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git
>   $ cd libtraceevent/
>   $ make
>   $ sudo make install
>   $ cd ..
>   $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git
>   $ cd libtracefs/
>   $ make
>   $ sudo make install
>   $ cd ..
>   $ sudo dnf install python3-docutils procps-devel
>   $ cd $rtla_src
>   $ make
>   $ sudo make install

Set osnoise/x to DEADLINE, the return is not success. see:

tao@geo ~/opensource/rtla-0.4 $ sudo rtla osnoise top -P d:100us:1ms -c 0-3 -r 900000 -d 1M -q
boost_with_deadline failed to boost pid 4766: Operation not permitted
Failed to set sched parameters

top shows:

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND         
 4773 root      20   0       0      0      0 R  89.4   0.0   2:06.88 osnoise/0       
 4776 root      20   0       0      0      0 R  89.4   0.0   2:06.88 osnoise/3       
 4774 root      20   0       0      0      0 R  89.0   0.0   2:06.88 osnoise/1       
 4775 root      20   0       0      0      0 R  88.7   0.0   2:06.69 osnoise/2       

 t