Re: [PATCH bpf-next v9 00/34] bpf: switch to memcg-based memory accounting

[Roman Gushchin]

On Wed, Dec 02, 2020 at 06:54:46PM -0800, Alexei Starovoitov wrote:
> On Tue, Dec 1, 2020 at 1:59 PM Roman Gushchin <guro@xxxxxx> wrote:
> >
> > 5) Cryptic -EPERM is returned on exceeding the limit. Libbpf even had
> >    a function to "explain" this case for users.
> ...
> > v9:
> >   - always charge the saved memory cgroup, by Daniel, Toke and Alexei
> >   - added bpf_map_kzalloc()
> >   - rebase and minor fixes
> 
> This looks great. Applied.

Thanks!

> Please follow up with a change to libbpf's pr_perm_msg().
> That helpful warning should stay for old kernels, but it would be
> misleading for new kernels.
> libbpf probably needs a feature check to make this warning conditional.

I think we've discussed it several months ago and at that time we didn't
find a good way to check this feature. I'll think again, but if somebody
has any ideas here, I'll appreciate a lot.