Re: [Report] rtla: Failed to set runtime and/or period

[Daniel Wagner <wagi@monom.org>]

On Thu, Sep 12, 2024 at 06:58:02PM GMT, Muhammad Usama Anjum wrote:
> We are running rt-tests on KernelCI. I'm looking at failures and I found
> out that rtla osnoise and rtla timerlat are failing. We have just
> enabled these tests and they are failing from day one.

Thanks a lot on working on this!

> The first thing I fixed in my local setup is to sync the version of rtla
> with that of the running kernel from the source. It resolves the Tracer
> timerlat not found!" error as we had installed the older rtla package
> from Debian on CI.

There is some dependency between kernel version and the rtla tool suite.
I suppose there is a window of version which you can differ but I
suppose the Debian packaged version is way too old for recent kernels.

> I'll update it. Is the version of rtla dependent on
> the exact kernel version or any recent rtla version is acceptable?

I have to figure this out. It could be that we need to build/provide
matching rtla versions to the kernel. In theory the API should be stable
etc but I suspect the APIs got broken (not on purpose) in the early
days. Anyway, we have to figure this out as we can't ask Daniel sadly.

> The other errors are persistent:
> 
> ➜  sudo ./rtla osnoise hist -r 900000
> Failed to set runtime and/or period
> Could not apply config

This works on my Tumbleweed kernel (pretty much a vanila kernel)
6.10.9-1-default with the matching rtla version 6.10.9.

What version do you use?

> I thought maybe some argument are wrong. I ran the example from man page:
> 
> ➜  sudo ./rtla osnoise hist -P F:1 -c 0-11 -r 900000 -d 1M -b 10 -E 25
> Failed to apply CPUs config
> Could not apply config

Same here. This works on my local kernel.

> Is there some configuration which is missing for running rtla? Please
> let me know.

Are these

    CONFIG_OSNOISE_TRACER
    CONFIG_TIMERLAT_TRACER

config option enabled in your kernel?

Thanks,
Daniel