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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lMO6jvaE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lMO6jvaE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BF1A1F000E9; Mon, 3 Aug 2026 18:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785781521; bh=0sUXbnPU3ypsUVe6qUTK39ZKfehy3OvmT4Rhxz8t7H8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=lMO6jvaEp/dcYZ1KE1EmHXF9cs5Or5q1Pj9k0NkcoQuRN1srZ2jw9n7YSF18kWrp2 nvqTFIBIszbkVYiFnGmv1VAKb+JY+VLHgKDn6CuenFc0pJGREJFprgTrd2ne2tIaS8 kKd5/+qawekRKrp5ejw1dhMf/JO2vhRA/ofzJSNUX7QfJfDo31gyH/UooRbPclyeLE muRWP7RC7IvMznAtua0VnCLGhvs2ioHRijEkMHeNLy4jsscogYYW1+/AT3S+dKW+gt KwmoIxO3VPXFggm26/ih7kYGe+4guJQ3BKWVY+8VY0e21nyVgzD5DP8/BBhHZcGfZ7 HMQOMkGUj0zXg== Date: Mon, 3 Aug 2026 15:25:14 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ian Rogers , Adrian Hunter , James Clark , Jiri Olsa , linux-perf-users@vger.kernel.org, Linux Kernel Mailing List Subject: Re: Flaky tests Message-ID: References: Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 31, 2026 at 04:32:38PM -0700, Namhyung Kim wrote: > On Sun, Jul 26, 2026 at 08:52:36PM -0300, Arnaldo Carvalho de Melo wrote: > > On Sun, Jul 26, 2026 at 08:22:08PM -0300, Arnaldo Carvalho de Melo wrote: > > > ⬢ [acme@toolbx perf-tools-next]$ git log --oneline -1 > > > 98bc7deff4858aa8 (HEAD -> perf/hardening-machine, number/perf/hardening-machine) perf machine: Check snprintf truncation for guest kallsyms path > > > ⬢ [acme@toolbx perf-tools-next]$ perf -v > > > perf version 7.2.rc1.g98bc7deff485 > > > ⬢ [acme@toolbx perf-tools-next]$ > > > logout > > > acme@x1:~/git/perf-tools-next$ > > > acme@x1:~/git/perf-tools-next$ sudo su - > > > [sudo] password for acme: > > > root@x1:~# perf -vv > > > perf version 7.2.rc1.g98bc7deff485 > > > aio: [ on ] # HAVE_AIO_SUPPORT > > > bpf: [ on ] # HAVE_LIBBPF_SUPPORT > > > bpf_skeletons: [ on ] # HAVE_BPF_SKEL > > > debuginfod: [ on ] # HAVE_DEBUGINFOD_SUPPORT > > > dwarf: [ on ] # HAVE_LIBDW_SUPPORT > > > dwarf_getlocations: [ on ] # HAVE_LIBDW_SUPPORT > > > dwarf-unwind: [ on ] # HAVE_DWARF_UNWIND_SUPPORT > > > libbfd: [ OFF ] # HAVE_LIBBFD_SUPPORT ( tip: Deprecated, license incompatibility, use BUILD_NONDISTRO=1 and install binutils-dev[el] ) > > > babeltrace2-ctf-writer: [ on ] # HAVE_BABELTRACE2_CTF_WRITER_SUPPORT > > > libbpf-strings: [ on ] # HAVE_LIBBPF_STRINGS_SUPPORT > > > libcapstone: [ on ] # HAVE_LIBCAPSTONE_SUPPORT > > > libdw-dwarf-unwind: [ on ] # HAVE_LIBDW_SUPPORT > > > libelf: [ on ] # HAVE_LIBELF_SUPPORT > > > libLLVM: [ on ] # HAVE_LIBLLVM_SUPPORT > > > libnuma: [ on ] # HAVE_LIBNUMA_SUPPORT > > > libopencsd: [ on ] # HAVE_CSTRACE_SUPPORT > > > libperl: [ OFF ] # HAVE_LIBPERL_SUPPORT ( tip: Deprecated, use LIBPERL=1 and install perl-ExtUtils-Embed/libperl-dev to build with it ) > > > libpfm4: [ on ] # HAVE_LIBPFM > > > libpython: [ on ] # HAVE_LIBPYTHON_SUPPORT > > > libslang: [ on ] # HAVE_SLANG_SUPPORT > > > libtraceevent: [ on ] # HAVE_LIBTRACEEVENT > > > libunwind: [ OFF ] # HAVE_LIBUNWIND_SUPPORT ( tip: Deprecated, use LIBUNWIND=1 and install libunwind-dev[el] to build with it ) > > > lzma: [ on ] # HAVE_LZMA_SUPPORT > > > numa_num_possible_cpus: [ on ] # HAVE_LIBNUMA_SUPPORT > > > zlib: [ on ] # HAVE_ZLIB_SUPPORT > > > zstd: [ on ] # HAVE_ZSTD_SUPPORT > > > rust: [ on ] # HAVE_RUST_SUPPORT > > > root@x1:~# perf test > [SNIP] > > > === Test Summary === > > > Passed main tests : 133 > > > Passed subtests : 152 > > > Skipped tests : 24 > > > Failed tests : 2 > > > List of failed tests: > > > 23: Object code reading > > > 110: perf record sample filtering (by BPF) tests > > > root@x1:~# perf test 23 > > > 23: Object code reading : Ok > > Right, I'm seeing this is flaky. Sometimes it fails to find a map for > some kernel address. > > > > > > > === Test Summary === > > > Passed main tests : 1 > > > Passed subtests : 0 > > > Skipped tests : 0 > > > Failed tests : 0 > > > root@x1:~# perf test 110 > > > 110: perf record sample filtering (by BPF) tests : Ok > > I never saw this before. Do you have error message? So, I just ran 'perf test -vvv', i.e. everything and in parallel, when I run it alone it works, but together with the other tests: 110: perf record sample filtering (by BPF) tests: ---- start ---- test child forked, pid 195512 Checking BPF-filter privilege Basic bpf-filter test Basic bpf-filter test [Success] Failing bpf-filter test Failing bpf-filter test [Success] Group bpf-filter test Group bpf-filter test [Failed forbidden CPU] ---- end(-1) ---- 110: perf record sample filtering (by BPF) tests : FAILED! Alone: root@x1:~# perf test 110 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 root@x1:~# perf stat --repeat 5 --null perf test 110 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 110: perf record sample filtering (by BPF) tests : Ok === Test Summary === Passed main tests : 1 Passed subtests : 0 Skipped tests : 0 Failed tests : 0 Performance counter stats for 'perf test 110' (5 runs): 13.785992473 +- 0.048784821 seconds time elapsed ( +- 0.35% ) root@x1:~#