Re: [RFC PATCH 2/4] tracing/probes: Compile all fetchargs into a single BPF program per event

[Alexei Starovoitov]

On Wed Jul 1, 2026 at 11:47 AM PDT, Steven Rostedt wrote:
> On Wed, 01 Jul 2026 11:41:26 -0700
> "Alexei Starovoitov" <alexei.starovoitov@xxxxxxxxx> wrote:
>
>> Nack.
>> I really don't like it.
>
> So the nack is mostly your opinion and not technical?
>
>> There were days in the past when the kernel generating bpf directly was appealing.
>> These days are gone. Performance improvements for fetchargs is not a good reason
>
> Why is performance *not* a good reason?
>
>> to add all this complexity and bypass verifier checks.
>
> The code lives in the kernel. What reason is there to add verification
> checks? The point of verification is because we don't trust user space. Why
> do we not trust the kernel?
>
>> bpf insns should come from user space.
>
> Why?

because I see this patchset as pointless kernel bloat with the "help" of bpf.
Hence the nack to avoid dragging bpf into this.

Call it philosophical disagreement if you like.