Re: [PATCHv3 perf/core 0/7] Reuse libbpf from samples/bpf

From: Arnaldo Carvalho de Melo
Date: Thu Dec 15 2016 - 10:35:25 EST

Em Thu, Dec 15, 2016 at 11:33:29AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, Dec 14, 2016 at 02:46:23PM -0800, Joe Stringer escreveu:
> > On 14 December 2016 at 06:55, Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> > > So, Joe, can you try refreshing this work, starting from what I have in
> > > perf/core? It has the changes coming from net-next that Daniel warned us about
> > > and some more.
> > I've just respun this series based on the version you previously
> > applied to perf/core. Since bpf_prog_{attach,detach}() were added to
> > samples/libbpf, a new patch will shift these over to tools/lib/bpf.
> > Other than that, I folded "samples/bpf: Drop unnecessary build
> > targets." back into "samples/bpf: Switch over to libbpf", and I
> > noticed that there were a couple of unnecessary log buffers with the
> > latest changes. For any new sample programs, those were fixed up to
> > use libbpf as well.
> > Don't forget to do a "make headers_install" before attempting to build
> > the samples, access to the latest headers is required (as per the
> > readme in samples/bpf).
> Ah, README, I should read that ;-)
> I got used to how tools/perf/ work, i.e. it is self sufficient wrt
> in-flux stuff in the kernel, i.e. headers that are related to features
> it supports and that are under constant improvements, such as eBPF, kvm,
> syscall tables, etc.
> Anyway, will do the headers_install step inside a container, to avoid
> polluting my workstation.

heh: should've read that file, now I did:

There are usually dependencies to header files of the current kernel.
To avoid installing devel kernel headers system wide, as a normal
user, simply call::

make headers_install

This will creates a local "usr/include" directory in the git/build top
level directory, that the make system automatically pickup first.

> Thanks for doing the respin and for the clarifications about building
> samples/bpf/.
> - Arnaldo