Re: [PATCH v1 2/8] tracing/ftrace: guard syscall probe with preempt_notrace

[Mathieu Desnoyers]

On 2024-10-04 16:52, Steven Rostedt wrote:
> On Fri, 4 Oct 2024 10:19:36 -0400
> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>
> > The eBPF people want to leverage this. When I last discussed this with
> > eBPF maintainers, they were open to adapt eBPF after this infrastructure
> > series is merged. Based on this eBPF attempt from 2022:
> >
> > https://lore.kernel.org/lkml/c323bce9-a04e-b1c3-580a-783fde259d60@xxxxxx/
>
> Sorry, I wasn't part of that discussion.
>
> > The sframe code is just getting in shape (2024), but is far from being ready.
> >
> > Everyone appears to be waiting for this infrastructure work to go in
> > before they can build on top. Once this infrastructure is available,
> > multiple groups can start working on introducing use of this into their
> > own code in parallel.
> >
> > Four years into this effort, and this is the first time we're told we need
> > to adapt in-tree tracers to handle the page faults before this can go in.
> >
> > Could you please stop moving the goal posts ?
>
> I don't think I'm moving the goal posts. I was mentioning to show an
> in-tree user. If BPF wants this, I'm all for it. The only thing I saw was a
> generalization in the cover letter about perf, bpf and ftrace using
> faultible tracepoints. I just wanted to see a path for that happening.

AFAIU eBPF folks are very eager to start making use of this, so we won't
have to wait long.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com