From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EDA6C30633 for ; Thu, 17 Aug 2023 14:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352284AbjHQOsx (ORCPT ); Thu, 17 Aug 2023 10:48:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352287AbjHQOs0 (ORCPT ); Thu, 17 Aug 2023 10:48:26 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A2BA23AA2; Thu, 17 Aug 2023 07:48:08 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5E2A61515; Thu, 17 Aug 2023 07:48:38 -0700 (PDT) Received: from donnerap.manchester.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4E3903F793; Thu, 17 Aug 2023 07:47:56 -0700 (PDT) Date: Thu, 17 Aug 2023 15:47:54 +0100 From: Andre Przywara To: Shuah Khan Cc: Shuah Khan , Nhat Pham , Johannes Weiner , linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] selftests: cachestat: test for cachestat availability Message-ID: <20230817154754.278218ae@donnerap.manchester.arm.com> In-Reply-To: <59c0fcd1-a1f2-de37-c94d-76687934acd5@linuxfoundation.org> References: <20230815155612.2535947-1-andre.przywara@arm.com> <20230815155612.2535947-4-andre.przywara@arm.com> <59c0fcd1-a1f2-de37-c94d-76687934acd5@linuxfoundation.org> Organization: ARM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Aug 2023 11:11:49 -0600 Shuah Khan wrote: Hi, > On 8/15/23 09:56, Andre Przywara wrote: > > As cachestat is a new syscall, it won't be available on older kernels, > > for instance those running on a build machine. In this case, a run > > reports all tests as "not ok" at the moment. > > > > Test for the cachestat syscall availability first, before doing further > > tests, and bail out early with a TAP SKIP comment. > > > > This also uses the opportunity to add the proper TAP headers, and add > > one check for the syscall error handling (illegal file descriptor). > > > > Signed-off-by: Andre Przywara > > --- > > .../selftests/cachestat/test_cachestat.c | 22 ++++++++++++++++++- > > 1 file changed, 21 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c > > index a5a4ac8dcb76c..77620e7ecf562 100644 > > --- a/tools/testing/selftests/cachestat/test_cachestat.c > > +++ b/tools/testing/selftests/cachestat/test_cachestat.c > > @@ -15,6 +15,8 @@ > > > > #include "../kselftest.h" > > > > +#define NR_TESTS 8 > > + > > static const char * const dev_files[] = { > > "/dev/zero", "/dev/null", "/dev/urandom", > > "/proc/version", "/proc" > > @@ -235,7 +237,25 @@ bool test_cachestat_shmem(void) > > > > int main(void) > > { > > - int ret = 0; > > + int ret; > > + > > + ksft_print_header(); > > + > > + ret = syscall(__NR_cachestat, -1, NULL, NULL, 0); > > + if (ret == -1 && errno == ENOSYS) { > > + printf("1..0 # Skipped: cachestat syscall not available\n"); > > + return KSFT_SKIP; > What happens when other errors besides ENOSYS? The test shouldn't > continue. -1 is an illegal file descriptor, and this is checked below (still using the same ret and errno), but reported using the normal framework. This check above is done early, before we even announce the plan, so that we can skip *all* of the tests, since they don't make any sense when the syscall is not available at all. Does that make sense? Cheers, Andre > > > + } > > + > > + ksft_set_plan(NR_TESTS); > > + > > + if (ret == -1 && errno == EBADF) { > > + ksft_test_result_pass("bad file descriptor recognized\n"); > > + ret = 0; > > + } else { > > + ksft_test_result_fail("bad file descriptor ignored\n"); > > + ret = 1; > > + } > > > > for (int i = 0; i < 5; i++) { > > const char *dev_filename = dev_files[i]; > > thanks, > -- Shuah