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

[Cyril Hrubis]

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.

Let's start with this, it would be a bit nicer if it returned EAGAIN
instead of EPERM at least. Will you send the email or should I?

> 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.

Let's go with a comment for now, we can add code later on once we are
clear on what is the expected outcome.

-- 
Cyril Hrubis
chrubis@suse.cz