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 31FF7ECAAD5 for ; Tue, 6 Sep 2022 18:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbiIFSbS (ORCPT ); Tue, 6 Sep 2022 14:31:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229526AbiIFSbR (ORCPT ); Tue, 6 Sep 2022 14:31:17 -0400 Received: from mail-ot1-f43.google.com (mail-ot1-f43.google.com [209.85.210.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEBE232056; Tue, 6 Sep 2022 11:31:16 -0700 (PDT) Received: by mail-ot1-f43.google.com with SMTP id l5-20020a05683004a500b0063707ff8244so8618724otd.12; Tue, 06 Sep 2022 11:31:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=KTMC4sgGs4iMTIRHGtHX14ygc35A9XeknD+0EJXhRfs=; b=tuB3YEpGuU0bj3K2vM2zYY5zKFkkLbBkhtKfkzXAO8IgevDSoE5OF9CdNAB0Szt71A Mv68yu3e/cBo2gkqWQiLg+M2ApFFRvKDjImDOh+zOwqyAvFyJmJ/aXWi5Vv89E/gsS6P x/t08t1kOP26ooHXQfGrpY2U2F0yXz8Poyo36ySe1x0PTip9nHKasEmCwFQ8kgykc8Mr dSaqlBOr42/cJW+xxlxoO2YLbhxf5L/4n4voJ0q0JOh6uubhWh7dU/dLdRYtX0jckHLA wZqSNr20zPGN5X2Fkn+Mu+IiMke1UpWQUG3rFWGSm0ry/ppsbNRNHvGccnffJGPFi8B/ PGjQ== X-Gm-Message-State: ACgBeo12Qg6KBeIiXGSTskVNAkSjDyGOhYgrXM6p/D/fEijPXwy/kc/o ng0kSFNOjux/y4Mxm+FiItuLp7l9DVHkyGbEYR4ZUdO2 X-Google-Smtp-Source: AA6agR5wIKuqeybuaOjh8IZNxiROzu/OFeaNSVGnVmevPf9aFwUSW1gEMxZT2SMQ83z9S3QPMVk6pFV0NPNc9oeKCmw= X-Received: by 2002:a9d:6f18:0:b0:638:b4aa:a546 with SMTP id n24-20020a9d6f18000000b00638b4aaa546mr21388276otq.124.1662489075965; Tue, 06 Sep 2022 11:31:15 -0700 (PDT) MIME-Version: 1.0 References: <20220903000210.1112014-1-namhyung@kernel.org> In-Reply-To: From: Namhyung Kim Date: Tue, 6 Sep 2022 11:31:04 -0700 Message-ID: Subject: Re: [PATCH] perf test: Skip sigtrap test on old kernels To: Arnaldo Carvalho de Melo Cc: Marco Elver , Jiri Olsa , Ingo Molnar , Peter Zijlstra , LKML , Ian Rogers , linux-perf-users Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Tue, Sep 6, 2022 at 5:45 AM Arnaldo Carvalho de Melo wrote: > > Em Sat, Sep 03, 2022 at 08:52:01AM +0200, Marco Elver escreveu: > > On Sat, 3 Sept 2022 at 02:02, Namhyung Kim wrote: > > > > > > If it runs on an old kernel, perf_event_open would fail because of the > > > new fields sigtrap and sig_data. Just skip the test if it failed. > > > > > > Cc: Marco Elver > > > Signed-off-by: Namhyung Kim > > > --- > > > tools/perf/tests/sigtrap.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/tools/perf/tests/sigtrap.c b/tools/perf/tests/sigtrap.c > > > index e32ece90e164..7057566e6ae4 100644 > > > --- a/tools/perf/tests/sigtrap.c > > > +++ b/tools/perf/tests/sigtrap.c > > > @@ -140,6 +140,7 @@ static int test__sigtrap(struct test_suite *test __maybe_unused, int subtest __m > > > fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag()); > > > if (fd < 0) { > > > pr_debug("FAILED sys_perf_event_open(): %s\n", str_error_r(errno, sbuf, sizeof(sbuf))); > > > + ret = TEST_SKIP; > > > > Wouldn't we be interested if perf_event_open() fails because it could > > actually be a bug? By skipping we'll be more likely to miss the fact > > there's a real problem. > > > > That's my naive thinking at least - what do other perf tests usually > > do in this case? > > Yeah, I was going to try and check if this is the only way that, with > the given arguments, perf_event_open would fail, but its better to at > least check errno against -EINVAL or something? EINVAL would be too generic and the kernel returns it in many places. I really wish we could have a better error reporting mechanism. Maybe we could retry perf_event_open with sigtrap and sig_data cleared. If it succeeded, then we can skip the test. If it still failed, then report the error. But it still couldn't find a bug in the sigtrap code. What do you think? Thanks, Namhyung