From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA48E49DB86; Mon, 28 Sep 2026 11:04:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790593447; cv=none; b=h/270x6A9l5hYJ0RfmPM4eC/0L8Lq68D/oJiYXgO5ZLC6PXxj+zYv+IZz4P4e28KkmUBmi77J0QVFOHksyuD0vLEG5g3qAozIAIk7wycw0+g60RezgTuNtVMmXOKR3mlqALP5D5A+Es9GkW3YljKTy1JoySLTGRG9Rxh86whKUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790593447; c=relaxed/simple; bh=6DTY0+Gm+vHfwDi/F4N3wGzRsYsSflT4f6vboBzK/Fk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=B6fC62NjvBpf+yJ0ab7P8xBxB/9Y6OCqRIVUxG1R8wwMH5MYwD+lYrXc+aM5w/I8H4JWVPlOvAUsI5bUVqbQFZ+aDEVf616SHaSF6Onij9kX7SgiliIOC0eY/JKVTNA5YDX4TH9ycNFkoEb4x+hf2VfTJuaERgCyDaoJgGCvGd0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DJaay7PG; 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="DJaay7PG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D15191F000FF; Mon, 28 Sep 2026 11:04:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790593446; bh=iKzxJQmNYQsUt2PEmdmsZav4S/mmfjAvnn3I6ZHTKf4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=DJaay7PGP72R0tGkgyP+Oia4imEuYm8t8qR2pXFgrg9WILqzSl7Vjhp2rqDjHKhux uDvrW2JpIyiASNUHIEFPZCnwPdOnC86ajBo8MeUmgKWcO1RGq3jtrAcpsqaC2H/gSN YN8/cyXRUqo+vKyymEyDaWP/qu79jZshTmfGQWuhHsZgZlrxlBA4TpI5fBeUFX/zP9 Q5IWXT00yBQBnN09zoLUi1pomgDek0CrQ7diRBg3IxLLnE22BgtzKyel6+XVNdLMUg BUbrKXD6vrPDCndd/xW8t3MDQHdtA92TFc5Ucd4FjBjsCfi2hMUSQGyF4YZtKTsPIl GRMJ5Vp+/rHuA== Date: Mon, 28 Sep 2026 12:03:58 +0100 From: "Lorenzo Stoakes (ARM)" To: Hajime Tazaki Cc: linux-mm@kvack.org, liam@infradead.org, rbm@suse.com, akpm@linux-foundation.org, luto@amacapital.net, brendan.jackman@linux.dev, david@kernel.org, liuhangbin@gmail.com, corbet@lwn.net, kees@kernel.org, broonie@kernel.org, mhocko@suse.com, rppt@kernel.org, shuah@kernel.org, surenb@google.com, vbabka@kernel.org, wad@chromium.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-um@lists.infradead.org, geert@linux-m68k.org, daniel@thingy.jp Subject: Re: [PATCH v3 2/3] selftests: run tests on nommu architecture Message-ID: References: <20260926010819.604346-1-thehajime@gmail.com> <20260926010819.604346-3-thehajime@gmail.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260926010819.604346-3-thehajime@gmail.com> On Sat, Sep 26, 2026 at 10:08:18AM +0900, Hajime Tazaki wrote: > Architectures lacks MMU doesn't support fork(2) syscall and only > vfork(2) is available with limitations. Thus, we cannot run kselftest > on nommu architecture as is. > > This commit addresses this issue with the following changes: > > - on test run stage, avoid calling timeout command when NOMMU=1 variable > added to environmental variable, since timeout command uses fork > syscall which nommu platform doesn't support. > - describe the difference of nommu tests in the document. > > So command line to build/execute tests for nommu should be like below: > > $ make ARCH=um NOMMU=1 O=build kselftest-all TARGETS=nommu > $ make ARCH=um NOMMU=1 O=build kselftest-install TARGETS=nommu > $ NOMMU=1 ./build/kselftest/kselftest_install/run_kselftest.sh -p \ > -c nommu > > Cc: Shuah Khan > Cc: Jonathan Corbet > Cc: Kees Cook > Cc: Andy Lutomirski > Cc: Will Drewry > Cc: Mark Brown > Cc: Brendan Jackman > Cc: Hangbin Liu > Cc: "Ricardo B. Marliere" > Cc: linux-kselftest@vger.kernel.org > Cc: linux-um@lists.infradead.org > Cc: linux-mm@kvack.org > Cc: linux-doc@vger.kernel.org > Closes: https://sashiko.dev/#/patchset/20260813063401.1786548-1-thehajime%40gmail.com > Signed-off-by: Hajime Tazaki LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > > -- > > v2 => v3 > - remove unnecessary modification > - new target is moved from TARGETS=mm/nommu to TARGETS=nommu > - rename CONFIG_NOMMU to NOMMU to avoid confusion to kernel config > > rfc => v2 > - reformat ktap header, reported by Sashiko review > - https://lore.kernel.org/linux-mm/20260825015945.141739-2-thehajime@gmail.com/ > > rfc: https://lore.kernel.org/linux-mm/20260813063401.1786548-1-thehajime@gmail.com/ > --- > Documentation/dev-tools/kselftest.rst | 14 ++++++++++++++ > tools/testing/selftests/kselftest/runner.sh | 6 +++++- > 2 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst > index 64c0ec7428a2..c35b819947b7 100644 > --- a/Documentation/dev-tools/kselftest.rst > +++ b/Documentation/dev-tools/kselftest.rst > @@ -230,6 +230,20 @@ section:: > > .. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompress > > +Build and test on nommu target > +============================== > + > +If you (cross-)build kselftests for nommu targets, or run tests on nommu targets, use > +``NOMMU=1`` as a make variable/environment setting to tell build system to do the additional > +checks. These nommu targets may differ in several ways, such as not supporting fork(2) or > +using musl or another libc. Set this variable to apply the necessary build and test adjustments. > + > +:: > + > + $ make ARCH=um NOMMU=1 O=build kselftest-all TARGETS=nommu # <= build-only > + $ make ARCH=um NOMMU=1 O=build kselftest-install TARGETS=nommu > + $ NOMMU=1 ./build/kselftest/kselftest_install/run_kselftest.sh -p -c nommu > + > Contributing new tests > ====================== > > diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh > index 8fc1018d6fec..95b5ebb8bbb9 100644 > --- a/tools/testing/selftests/kselftest/runner.sh > +++ b/tools/testing/selftests/kselftest/runner.sh > @@ -38,8 +38,12 @@ tap_prefix() > > tap_timeout() > { > + # nommu doesn't support timeout command (missing fork(2)) > + if [ "$NOMMU" = "1" ] ; then > + echo "timeout isn't supported for NOMMU" > + $1 > # Make sure tests will time out if utility is available. > - if [ -x /usr/bin/timeout ] ; then > + elif [ -x /usr/bin/timeout ] ; then > /usr/bin/timeout --foreground "$kselftest_timeout" \ > /usr/bin/timeout "$kselftest_timeout" $1 > else > -- > 2.43.0 > -- Cheers, Lorenzo