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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 3F9E7C2D0EF for ; Fri, 17 Apr 2020 18:46:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20C4622201 for ; Fri, 17 Apr 2020 18:46:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RfQfUsRC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729409AbgDQSqD (ORCPT ); Fri, 17 Apr 2020 14:46:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727840AbgDQSqC (ORCPT ); Fri, 17 Apr 2020 14:46:02 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FA95C061A0C for ; Fri, 17 Apr 2020 11:46:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VuZsWEhfzTLuKGA1NHD95YdTHFY/ejA3z6ZEjfk5sbs=; b=RfQfUsRCI/Tm6COLEP0qv9xl8M 9LwJZgSkrVJLotE94dvoWdnWSVAXgO2ykdMQclgybPk5xDIkGxKsuac9j+I42/hFQj48q1R/FIpoB Dqn2fqpRqVWdpzRp8yGQ1erZ9mIpyhNIQIH/SLYIxbrm+6uARErB3Asitu97JGMXbfMvDaMwZhfG+ Afck5MbOiNB2QEWEr+EM74NILZfdfZKozuGoBp/9OdmvnEHOCED0/eAGpn6nZs6FzHWjvhR61MwhY LRCtR5oof7b/+lovYI0UuUZCBnCF8b0AhKboGbJQ4Cn3eYqVvzSrpsLo03vsrIglnpFpI5L+N5SV/ FKKpWTEA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jPVzd-00083Z-VF; Fri, 17 Apr 2020 18:45:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 74A823010BC; Fri, 17 Apr 2020 20:45:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4F8B02B12520A; Fri, 17 Apr 2020 20:45:36 +0200 (CEST) Date: Fri, 17 Apr 2020 20:45:36 +0200 From: Peter Zijlstra To: Ian Rogers Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Stephane Eranian , KP Singh Subject: Re: [PATCH] perf/core: fix parent pid/tid in task exit events Message-ID: <20200417184536.GK20730@hirez.programming.kicks-ass.net> References: <20200417182842.12522-1-irogers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200417182842.12522-1-irogers@google.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 17, 2020 at 11:28:42AM -0700, Ian Rogers wrote: > Current logic yields the child task as the parent. > > Before: > $ perf record bash -c "perf list > /dev/null" > $ perf script -D |grep 'FORK\|EXIT' > 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470) > 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472) > 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470) > ^ > Note the repeated values here -------------------/ > > After: > 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266) > 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266) > 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265) > Fixes: .... ? > Reported-by: KP Singh > Signed-off-by: Ian Rogers