Re: linux-next: build failure after merge of the perf tree

Ian Rogers
2023-03-22T18:37:57Z

On Tue, Mar 21, 2023 at 2:40 PM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi all,
>
> On Fri, 17 Mar 2023 09:50:25 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > After merging the perf tree, today's linux-next build (native perf)
> > failed like this:
> >
> > Auto-detecting system features:
> > ... clang-bpf-co-re: [ [32mon [m ]
> > ... llvm: [ [31mOFF [m ]
> > ... libcap: [ [32mon [m ]
> > ... libbfd: [ [32mon [m ]
> >
> > make[1]: *** Deleting file '/home/sfr/next/perf/util/bpf_skel/vmlinux.h'
> > libbpf: failed to find '.BTF' ELF section in /boot/vmlinux-6.0.0-5-powerpc64le
> > Error: failed to load BTF from /boot/vmlinux-6.0.0-5-powerpc64le: No data available
> > make[1]: *** [Makefile.perf:1075: /home/sfr/next/perf/util/bpf_skel/vmlinux.h] Error 195
> > make[1]: *** Waiting for unfinished jobs....
> > make: *** [Makefile.perf:236: sub-make] Error 2
> > Command exited with non-zero status 2
> >
> > To be clear this is a native build of perf on a PPC64le host using this
> > command line:
> >
> > make -C tools/perf -f Makefile.perf -s -O -j60 O=../perf EXTRA_CFLAGS=-Wno-psabi
> >
> > (I could probably remove the EXTRA_CLFAGS now that I am building with
> > gcc 12.2)
> >
> > I don't know which commit caused this.
> >
> > I have used the perf tree from next-20230316 for today.
>
> I am still getting this build failure.

Hi Stephen,

The build failure is intentional as not having BPF skeleton support in
the perf tool will remove features. I've just sent:
https://lore.kernel.org/lkml/20230322183108.1380882-1-irogers@google.com/
Which will recommend adding NO_BPF_SKEL=1 to your build options when
this failure occurs. I didn't think a features test was appropriate
for this as the feature test would basically replicate the vmlinux.h
generation and I didn't want to move that support through the build
system.

Thanks,
Ian

> --
> Cheers,
> Stephen Rothwell