Re: [PATCH 2/2] sched/debug: add sched_update_nr_running tracepoint

From: Joel Fernandes
Date: Wed Sep 04 2019 - 11:41:50 EST


On Wed, Sep 04, 2019 at 08:37:22AM -0700, Alexei Starovoitov wrote:
> On Wed, Sep 4, 2019 at 8:33 AM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
> >
> > On Wed, Sep 04, 2019 at 08:26:52AM -0700, Alexei Starovoitov wrote:
> > > On Wed, Sep 4, 2019 at 6:14 AM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > True. However, for kprobes-based BPF program - it does check for kernel
> > > > version to ensure that the BPF program is built against the right kernel
> > > > version (in order to ensure the program is built against the right set of
> > > > kernel headers). If it is not, then BPF refuses to load the program.
> > >
> > > This is not true anymore. Users found few ways to workaround that check
> > > in practice. It became useless and it was deleted some time ago.
> >
> > Wow, Ok! Interesting!
>
> the other part of your email says about kernel header requirement.
> This is not true any more as well :)
> BTF relocations are already supported by the kernel, llvm, libbpf,
> bpftool, pahole.
> We'll be posting sample code soon.

Ok, this landscape seems to be changing quite a bit. I was going by what I
already know... Looking forward to catching up with the latest. Sorry,

thanks,

- Joel