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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7FE7BC433DB for ; Fri, 5 Mar 2021 17:17:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38BDE65051 for ; Fri, 5 Mar 2021 17:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229642AbhCERQ2 (ORCPT ); Fri, 5 Mar 2021 12:16:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:47266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229616AbhCERQ1 (ORCPT ); Fri, 5 Mar 2021 12:16:27 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 38B3F65051; Fri, 5 Mar 2021 17:16:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614964587; bh=/ltV4TybMsf7MDvvcwuffVYwQgFEEIM5tPdvWRCYeC8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MS3VOelF40Y31R0Y19cdZw9H5NADPXMXD2TJNQX01N8VpEDl+oh0iMbDdKJb3t6NW O1roDkbe8y+Gx2hVWECPjFzb/xsYr0NqyTYSbFFRAo7nry1Iwl9qMB0Myu6yRCTf1d FH2MdsCq7gCciRRxBrC+o9y8AkPP+3hKkJdKnaRrC0gbjdLNuKOnsb+WXRrJP9RQeG JfOX9nFlUzBelbOiYTxKFaAe6MSLsXehRXpZV+nWC68unOJA+bkfyVnd3L79S0KK4D B7HPKwj7dZDxuVahhUm1ycaYw0olZ/eaRJ4tFBRzrYMz/y7EHqdk0nG0iV9UQsWLR+ 9lU2SuslGoHyA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id DB86640647; Fri, 5 Mar 2021 14:16:24 -0300 (-03) Date: Fri, 5 Mar 2021 14:16:24 -0300 From: Arnaldo Carvalho de Melo To: Michael Petlan Cc: acme@redhat.com, linux-perf-users@vger.kernel.org, jolsa@redhat.com, Linux Kernel Mailing List Subject: Re: [PATCH] perf trace: Fix race in signal handling Message-ID: References: <20210302144120.17362-1-mpetlan@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210302144120.17362-1-mpetlan@redhat.com> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Em Tue, Mar 02, 2021 at 03:41:20PM +0100, Michael Petlan escreveu: > Since a lot of stuff happens before the SIGINT signal handler is registered > (scanning /proc/*, etc.), on bigger systems, such as Cavium Sabre CN99xx, > it may happen that first interrupt signal is lost and perf isn't correctly > terminated. > > The reproduction code might look like the following: > > perf trace -a & > PERF_PID=$! > sleep 4 > kill -INT $PERF_PID > > The issue has been found on a CN99xx machine with RHEL-8 and the patch fixes > it by registering the signal handlers earlier in the init stage. Thanks, applied. - Arnaldo > Suggested-by: Jiri Olsa > Signed-off-by: Michael Petlan > Tested-by: Michael Petlan > --- > tools/perf/builtin-trace.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c > index 85b6a46e85b6..7ec18ff57fc4 100644 > --- a/tools/perf/builtin-trace.c > +++ b/tools/perf/builtin-trace.c > @@ -3964,9 +3964,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv) > > evlist__config(evlist, &trace->opts, &callchain_param); > > - signal(SIGCHLD, sig_handler); > - signal(SIGINT, sig_handler); > - > if (forks) { > err = evlist__prepare_workload(evlist, &trace->opts.target, argv, false, NULL); > if (err < 0) { > @@ -4827,6 +4824,8 @@ int cmd_trace(int argc, const char **argv) > > signal(SIGSEGV, sighandler_dump_stack); > signal(SIGFPE, sighandler_dump_stack); > + signal(SIGCHLD, sig_handler); > + signal(SIGINT, sig_handler); > > trace.evlist = evlist__new(); > trace.sctbl = syscalltbl__new(); > -- > 2.18.4 > -- - Arnaldo