Getting a clean BPF selftests run involves ensuring latest trunk LLVM/clang are used, pahole is recent (>=1.16) and config matches the specified config file as closely as possible. Add to bpf_devel_QA.rst and point tools/testing/selftests/bpf/README.rst to it.

Signed-off-by: Alan Maguire alan.maguire@oracle.com Acked-by: Andrii Nakryiko andriin@fb.com --- Documentation/bpf/bpf_devel_QA.rst | 15 +++++++++++++++ tools/testing/selftests/bpf/README.rst | 2 ++ 2 files changed, 17 insertions(+)

diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index 38c15c6..0b3db91 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -437,6 +437,21 @@ needed:: See the kernels selftest `Documentation/dev-tools/kselftest.rst`_ document for further documentation.

+To maximize the number of tests passing, the .config of the kernel +under test should match the config file fragment in +tools/testing/selftests/bpf as closely as possible. + +Finally to ensure support for latest BPF Type Format features - +discussed in `Documentation/bpf/btf.rst`_ - pahole version 1.16 +is required for kernels built with CONFIG_DEBUG_INFO_BTF=y. +pahole is delivered in the dwarves package or can be built +from source at + +https://github.com/acmel/dwarves + +Some distros have pahole version 1.16 packaged already, e.g. +Fedora, Gentoo. + Q: Which BPF kernel selftests version should I run my kernel against? --------------------------------------------------------------------- A: If you run a kernel ``xyz``, then always run the BPF kernel selftests diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst index 0f67f1b..e885d35 100644 --- a/tools/testing/selftests/bpf/README.rst +++ b/tools/testing/selftests/bpf/README.rst @@ -1,6 +1,8 @@ ================== BPF Selftest Notes ================== +General instructions on running selftests can be found in +`Documentation/bpf/bpf_devel_QA.rst`_.

Additional information about selftest failures are documented here.