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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 AC565C3A5A3 for ; Fri, 30 Aug 2019 07:35:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B4B521897 for ; Fri, 30 Aug 2019 07:35:17 +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="ZNTTPb+C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728107AbfH3HfQ (ORCPT ); Fri, 30 Aug 2019 03:35:16 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48118 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725780AbfH3HfP (ORCPT ); Fri, 30 Aug 2019 03:35:15 -0400 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=jXZGykbK7fcCFdm1k42aGJ6dco0WwRrRvnakPuLcX6w=; b=ZNTTPb+CmszhANgH38A+BIutb DGT0soGfqg7qc/3wBwW5h/uOhVDqhow5wdji0O2TtcGJvv0Uv1Y1wuGw6VHzxfIks3NqcjV9TS7uU GlVg6rYQlQ4YAdUyDUkRQmd8NQScZEAq9fKwu+4gCbGMbFAB04+oERcrtgxdJnJBhGXWgipCuGkmB o+JTZSu4pX1TOareK5mhUWSsqDvNIrWqjZJ9f11XYwrL5bIpYbQAxDqKHpQVcy4+oJuMXZGouKZYc Uy4aHE3Ps0bCPKBtuJFFsYF1SlE5TK47C13mglAmAkgimI9IUo/zr9WOb++Bz5GyYVQ6Tp197x3M8 QYGf1iQyg==; 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 (Red Hat Linux)) id 1i3bQq-0008GY-7i; Fri, 30 Aug 2019 07:34:52 +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 3673030008D; Fri, 30 Aug 2019 09:34:13 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7D4F1202411AD; Fri, 30 Aug 2019 09:34:48 +0200 (CEST) Date: Fri, 30 Aug 2019 09:34:48 +0200 From: Peter Zijlstra To: Namhyung Kim Cc: Ingo Molnar , Arnaldo Carvalho de Melo , LKML , Jiri Olsa , Alexander Shishkin , Stephane Eranian , Tejun Heo , Li Zefan , Johannes Weiner , Adrian Hunter Subject: Re: [PATCH 1/9] perf/core: Add PERF_RECORD_CGROUP event Message-ID: <20190830073448.GZ2369@hirez.programming.kicks-ass.net> References: <20190828073130.83800-1-namhyung@kernel.org> <20190828073130.83800-2-namhyung@kernel.org> <20190828094459.GG2369@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 On Fri, Aug 30, 2019 at 12:46:51PM +0900, Namhyung Kim wrote: > Hi Peter, > > On Wed, Aug 28, 2019 at 6:45 PM Peter Zijlstra wrote: > > > > On Wed, Aug 28, 2019 at 04:31:22PM +0900, Namhyung Kim wrote: > > > To support cgroup tracking, add CGROUP event to save a link between > > > cgroup path and inode number. The attr.cgroup bit was also added to > > > enable cgroup tracking from userspace. > > > > > > This event will be generated when a new cgroup becomes active. > > > Userspace might need to synthesize those events for existing cgroups. > > > > > > As aux_output change is also going on, I just added the bit here as > > > well to remove possible conflicts later. > > > > Why do we want this? > > I saw below [1] and thought you have the patch introduced aux_output > and it's gonna to be merged soon. > Also the tooling patches are already in the acme/perf/core > so I just wanted to avoid conflicts. > > Anyway, I'm ok with changing it. Will remove in v2. I seem to have confused both you and Arnaldo with this. This email questions the Changelog as a whole, not just the aux thing (I send a separate email for that). This Changelog utterly fails to explain to me _why_ we need/want cgroup tracking. So why do I want to review and possibly merge this? Changelog needs to answer this.