BPF CI update: veristat-scx job

BPF CI update: veristat-scx job

[Ihor Solodrai]

Hi everyone.

In effort to improve testing of both BPF subsystem and sched-ext
project [1], a new testing workflow has been added to BPF CI:
veristat-scx.

veristat-kernel and veristat-meta jobs have been running for a while
now, and veristat-scx is basically adding more test cases using
sched-ext BPF programs as input.

For those who aren't aware, veristat [2] is a command line tool that
can be used to load BPF object files into the kernel and check
verification results, among other things. It's source code is at
./tools/testing/selftests/bpf/veristat.c

On BPF CI, veristat-${target} job takes BPF object files (determined
by ${target}) as input, and runs veristat on them against the kernel
under testing. In addition to checking whether BPF program is accepted
by the verifier, the CI job also collects verifier performance stats,
and compares them to the baseline *failing* if a significant
regression is detected.

See an example of successful job run here:
https://github.com/kernel-patches/bpf/actions/runs/15543439297/job/43761685117

[1] https://github.com/sched-ext/scx
[2] https://github.com/libbpf/veristat

Re: BPF CI update: veristat-scx job

[Andrii Nakryiko]

On Mon, Jun 9, 2025 at 2:30 PM Ihor Solodrai <ihor.solodrai@linux.dev> wrote:
>
> Hi everyone.
>
> In effort to improve testing of both BPF subsystem and sched-ext
> project [1], a new testing workflow has been added to BPF CI:
> veristat-scx.
>
> veristat-kernel and veristat-meta jobs have been running for a while
> now, and veristat-scx is basically adding more test cases using
> sched-ext BPF programs as input.
>
> For those who aren't aware, veristat [2] is a command line tool that
> can be used to load BPF object files into the kernel and check
> verification results, among other things. It's source code is at
> ./tools/testing/selftests/bpf/veristat.c
>
> On BPF CI, veristat-${target} job takes BPF object files (determined
> by ${target}) as input, and runs veristat on them against the kernel
> under testing. In addition to checking whether BPF program is accepted
> by the verifier, the CI job also collects verifier performance stats,
> and compares them to the baseline *failing* if a significant
> regression is detected.
>
> See an example of successful job run here:
> https://github.com/kernel-patches/bpf/actions/runs/15543439297/job/43761685117

Unsuccessful veristat runs are actually more interesting :) Do you
have a link to some examples with veristat failures?

>
> [1] https://github.com/sched-ext/scx
> [2] https://github.com/libbpf/veristat
>

Re: BPF CI update: veristat-scx job

[Ihor Solodrai]

On 6/9/25 2:43 PM, Andrii Nakryiko wrote:
> On Mon, Jun 9, 2025 at 2:30 PM Ihor Solodrai <ihor.solodrai@linux.dev> wrote:
>>
>> [...]
>>
>> See an example of successful job run here:
>> https://github.com/kernel-patches/bpf/actions/runs/15543439297/job/43761685117
> 
> Unsuccessful veristat runs are actually more interesting :) Do you
> have a link to some examples with veristat failures?

Here is a recent one (although it's not that interesting either):
https://github.com/kernel-patches/bpf/actions/runs/15496531493/job/43634843627

> 
>>
>> [1] https://github.com/sched-ext/scx
>> [2] https://github.com/libbpf/veristat
>>