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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8BBAC43441 for ; Wed, 28 Nov 2018 13:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B9B72086B for ; Wed, 28 Nov 2018 13:09:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="tL8Am1wT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B9B72086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728458AbeK2ALX (ORCPT ); Wed, 28 Nov 2018 19:11:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:54402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728044AbeK2ALW (ORCPT ); Wed, 28 Nov 2018 19:11:22 -0500 Received: from quaco.infradead.org (unknown [179.97.41.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 63ED720832; Wed, 28 Nov 2018 13:09:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543410585; bh=7YU7ZQXq/P3DtNilzh8wU9XZYduEwvEdBmJ4aX7+4YY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tL8Am1wTbjDucXgXlTHCKbwfoCZ+OO1n1QKf0EeDXkkoRbhXJqA6BC5zBsLL89Hr4 CpevFa36loYc055cZCvgb8b2wTp1m9LGQFpz/CMNLxjiZ+j8b8CyFm8etAnw09e54u Gjyizj5A5FD7mL5vRV+x5q+NFUQ0vyq1XJyYiZzs= Received: by quaco.infradead.org (Postfix, from userid 1000) id CD10340341; Wed, 28 Nov 2018 10:09:42 -0300 (-03) Date: Wed, 28 Nov 2018 10:09:42 -0300 From: Arnaldo Carvalho de Melo To: Adrian Hunter Cc: Jiri Olsa , linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf intel-pt: Fix error with config term pt=0 Message-ID: <20181128130942.GC31608@kernel.org> References: <20181127084336.12142-1-adrian.hunter@intel.com> <20181127123928.GB15747@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, Nov 28, 2018 at 02:38:13PM +0200, Adrian Hunter escreveu: > On 27/11/18 2:39 PM, Arnaldo Carvalho de Melo wrote: > > Em Tue, Nov 27, 2018 at 10:43:36AM +0200, Adrian Hunter escreveu: > >> Users should never use 'pt=0', but if they do it may give a meaningless > >> error: > >> > >> $ perf record -e intel_pt/pt=0/u uname > >> Error: > >> The sys_perf_event_open() syscall returned with 22 (Invalid argument) for > >> event (intel_pt/pt=0/u). > >> > >> Fix that by forcing 'pt=1'. > >> > >> Signed-off-by: Adrian Hunter > >> --- > >> tools/perf/arch/x86/util/intel-pt.c | 8 ++++++++ > >> 1 file changed, 8 insertions(+) > >> > >> diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c > >> index db0ba8caf5a2..af25a7824ee0 100644 > >> --- a/tools/perf/arch/x86/util/intel-pt.c > >> +++ b/tools/perf/arch/x86/util/intel-pt.c > >> @@ -524,10 +524,18 @@ static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu, > >> struct perf_evsel *evsel) > >> { > >> int err; > >> + char c; > >> > >> if (!evsel) > >> return 0; > >> > >> + /* > >> + * If supported, force pass-through config term (pt=1) even if user > >> + * sets pt=0, which avoids senseless kernel errors. > >> + */ > >> + if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1) > >> + evsel->attr.config |= 1; > > > > shouldn't we have a warning like: > > > > pr_warning("pt=0 doesn't make sense, forcing pt=1") > > > > > > Instead of silently doing something the user, mistakenly, did > > explicitely? > > Sure, here it is: Thanks, sticked this to the cset: ------------------------ Committer testing: # perf record -e intel_pt/pt=0/u uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_pt/pt=0/u). /bin/dmesg | grep -i perf may provide additional information. # perf record -e intel_pt/pt=0/u uname pt=0 doesn't make sense, forcing pt=1 Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.020 MB perf.data ] # ------------------------ Thanks, applied. - Arnaldo