Re: [PATCH bpf-next v2 29/35] bpf: libbpf: cleanup RLIMIT_MEMLOCK usage

[Song Liu]

On Mon, Jul 27, 2020 at 3:07 PM Andrii Nakryiko
<andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Mon, Jul 27, 2020 at 12:21 PM Roman Gushchin <guro@xxxxxx> wrote:
> >
> > As bpf is not using memlock rlimit for memory accounting anymore,
> > let's remove the related code from libbpf.
> >
> > Bpf operations can't fail because of exceeding the limit anymore.
> >
>
> They can't in the newest kernel, but libbpf will keep working and
> supporting old kernels for a very long time now. So please don't
> remove any of this.
>
> But it would be nice to add a detection of whether kernel needs a
> RLIMIT_MEMLOCK bump or not. Is there some simple and reliable way to
> detect this from user-space?
>

Agreed. We will need compatibility or similar detection for perf as well.

Thanks,
Song