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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 98584C43387 for ; Thu, 3 Jan 2019 07:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D05420896 for ; Thu, 3 Jan 2019 07:42:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730163AbfACHmU (ORCPT ); Thu, 3 Jan 2019 02:42:20 -0500 Received: from mga03.intel.com ([134.134.136.65]:47003 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726671AbfACHmU (ORCPT ); Thu, 3 Jan 2019 02:42:20 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Jan 2019 23:42:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,434,1539673200"; d="scan'208";a="122960980" Received: from skl.sh.intel.com ([10.239.159.132]) by FMSMGA003.fm.intel.com with ESMTP; 02 Jan 2019 23:42:17 -0800 From: Jin Yao To: acme@kernel.org, jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com Cc: Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com, Jin Yao Subject: [PATCH] perf stat: Fix endless wait for child process Date: Thu, 3 Jan 2019 15:40:45 +0800 Message-Id: <1546501245-4512-1-git-send-email-yao.jin@linux.intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We hit a perf stat issue by using following script. #!/bin/bash sleep 1000 & exec perf stat -a -e cycles -I1000 -- sleep 5 Since "perf stat" is launched by exec, so the "sleep 1000" would be the child process of "perf stat". The wait4() will not return because it's waiting for the child process "sleep 1000" to be end. So perf stat doesn't return even 5s passed. This patch lets the perf stat return when the specified child process is end (in this case, specified child process is "sleep 5"). Signed-off-by: Jin Yao --- tools/perf/builtin-stat.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 1410d66..63a3afc 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -561,7 +561,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) break; } } - wait4(child_pid, &status, 0, &stat_config.ru_data); + if (child_pid != -1) + wait4(child_pid, &status, 0, &stat_config.ru_data); if (workload_exec_errno) { const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg)); -- 2.7.4