Re: [RFC PATCH 3/6] tools: build perf in tools_build

[Sasha Levin <sashal@kernel.org>]

On Tue, Oct 13, 2026 at 05:21:25PM -0300, Arnaldo Carvalho de Melo wrote:
>Why is that difficult to run:
>
>make -C tools/perf install-build-deps
>
>To do a recommended perf build deps install?
>
>That would be useful as it is what we expect users to do.

That's what users do, but it wants to install packages.

We need a path for unprivileged builds on bots and CI machines that can't
install packages, and many of those builds are cross builds, where perf needs
the target's libelf and libtraceevent rather than the host's.

>If that is too difficult, for some reason, there is a minimal build in
>tools/perf/tests/make, that is tested since forever:
>
># all the NO_* variable combined
>make_minimal        := NO_PYTHON_MODULE=1
>make_minimal        += NO_DEMANGLE=1 NO_LIBELF=1 NO_BACKTRACE=1
>make_minimal        += NO_LIBNUMA=1 NO_LIBBIONIC=1 NO_LIBDW=1
>make_minimal        += NO_LIBBPF=1
>make_minimal        += NO_SDT=1 NO_JVMTI=1 NO_LIBZSTD=1
>make_minimal        += NO_CAPSTONE=1

I tried make_minimal on perf-tools-next. It still requires libtraceevent, so an
arm64 cross build without the arm64 libtraceevent installed stops at that
check. With NO_LIBTRACEEVENT=1 added, it then fails building the Rust test
workload. Natively it still enables aio, libLLVM, libslang, libtraceevent,
lzma, zlib and Rust when they are installed, so the result depends on the
machine.
  
I'd like to go with Ian's suggestion then: a MINIMAL=1 knob in perf that turns
off every optional feature, which tests/make can use for make_minimal as well.

-- 
Thanks,
Sasha