[LTP] [PATCH v4 0/4] Basic eBPF tests

[Jan Stancek]

----- Original Message -----
> Hi!
> > There's one EPERM I can reproduce reliably with bpf_map test, which appears
> > to originate from "bpf_charge_memlock".
> > 
> > There's a deferred component to map freeing, and unchange appears to be
> > part of it:
> >   bpf_map_release
> >     bpf_map_put
> >       INIT_WORK(&map->work, bpf_map_free_deferred);
> >         (deferred) bpf_uncharge_memlock
> > 
> > When I lower max locked memory, it's easy to hit:
> > # ulimit  -l 128; ./bpf_map01 -i 100
> > ...
> > bpf_map01.c:52: CONF: bpf() requires CAP_SYS_ADMIN on this system: EPERM
> > 
> > Can you try bumping max locked memory to some high value and check
> > if that helps your case?
> 
> Looks like this was the case, with high enough value the tests works
> without a problem. The question is if and/or what should be done about
> this...

We can try asking on bpf@vger.kernel.org, if they see it as bug.

I'd push tests with a comment. Or setup() that bumps the limit: whatever
current limit is, add 2MB to it, so single/few iteration(s) should always work.