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 C9F78C5519F for ; Fri, 27 Nov 2020 17:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B4E622252 for ; Fri, 27 Nov 2020 17:30:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="AlBjocCo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731935AbgK0RaY (ORCPT ); Fri, 27 Nov 2020 12:30:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:35554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730985AbgK0RaY (ORCPT ); Fri, 27 Nov 2020 12:30:24 -0500 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (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 9373122250; Fri, 27 Nov 2020 17:30:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606498223; bh=xmP8gcXuSDMVJyjkMa0hBLOirCsCrqhYvzLRXHrrROk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AlBjocCogPiRqU8mohInEWNBA/iXGN91/8RrU457W1oP3RNRwxQnfoPJ1WxbB0bRU lAxxH1IFPL095drpFYJKwL/5MISvXSLt59hZ+N6BfkKVjZ6uE1G5KE01eVGksdqpwI qq7n9MoHExSHhDmNCneZJWoDK1LSauuJIZRrlLaQ= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 7E93E40D0D; Fri, 27 Nov 2020 14:30:21 -0300 (-03) Date: Fri, 27 Nov 2020 14:30:21 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Namhyung Kim , Ingo Molnar , Peter Zijlstra , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Ian Rogers Subject: Re: [PATCH] perf record: Synthesize cgroup events only if needed Message-ID: <20201127173021.GN70905@kernel.org> References: <20201127054356.405481-1-namhyung@kernel.org> <20201127154557.GB2729821@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201127154557.GB2729821@krava> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Nov 27, 2020 at 04:45:57PM +0100, Jiri Olsa escreveu: > On Fri, Nov 27, 2020 at 02:43:56PM +0900, Namhyung Kim wrote: > > It didn't check the tool->cgroup_events bit which is set when > > the --all-cgroups option is given. Without it, samples will not have > > cgroup info so no reason to synthesize. > > > > We can check the PERF_RECORD_CGROUP records after running perf record > > *WITHOUT* the --all-cgroups option: > > > > Before: > > $ perf report -D | grep CGROUP > > 0 0 0x8430 [0x38]: PERF_RECORD_CGROUP cgroup: 1 / > > CGROUP events: 1 > > CGROUP events: 0 > > CGROUP events: 0 > > > > After: > > $ perf report -D | grep CGROUP > > CGROUP events: 0 > > CGROUP events: 0 > > CGROUP events: 0 > > > > Fixes: 8fb4b67939e16 ("perf record: Add --all-cgroups option") > > Signed-off-by: Namhyung Kim > > --- > > tools/perf/util/synthetic-events.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c > > index 8a23391558cf..d9c624377da7 100644 > > --- a/tools/perf/util/synthetic-events.c > > +++ b/tools/perf/util/synthetic-events.c > > @@ -563,6 +563,9 @@ int perf_event__synthesize_cgroups(struct perf_tool *tool, > > char cgrp_root[PATH_MAX]; > > size_t mount_len; /* length of mount point in the path */ > > > > + if (!tool || !tool->cgroup_events) > > + return 0; > > can !tool actually happen here? or it's just being extra cautious > > Acked-by: Jiri Olsa Thanks, tested with/without --all-cgroups and applied. - Arnaldo