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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 BDF88C433E3 for ; Fri, 24 Jul 2020 13:54:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96D8720656 for ; Fri, 24 Jul 2020 13:54:21 +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="Pav7lQzp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726988AbgGXNyU (ORCPT ); Fri, 24 Jul 2020 09:54:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726535AbgGXNyT (ORCPT ); Fri, 24 Jul 2020 09:54:19 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E9E7C0619D3 for ; Fri, 24 Jul 2020 06:54:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=B8eRNxs9htmGJHGObFBZh5ZETBX8Pkz8XXY1/7/EoIw=; b=Pav7lQzprIg8yZ9L799/Y4KMa3 6iNLrGbH977obkzOva0ADwPFK5cJuComOE/l+sGysGynFSTHhitCXoIuaDya4YNLGQHne/0wK7s3R air6SWLRzIa630nyc5x0thZ80Oe3CK/xNQqwyeqMKdaoNpMEXSbgYX4t8hTl++4eQZAtniSf5ASYw kzcJW3XDkaJLoWRX/eX/4Ut/m2MhYZoVeGZ9EQasijOVEytC6GUJtjM19acclHhJEqlbdXD4xZZSI om/5DITubutoKVYkjDKiHoCKUcSxR7MS1UXdC4ed25cUBiMoDRPaEbrZfm2EkXuDBMvQvm2EummJr CYsryBMg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyy9N-0002GD-4w; Fri, 24 Jul 2020 13:54:13 +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 442F33060EF; Fri, 24 Jul 2020 15:54:12 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2D7A9236F1EA4; Fri, 24 Jul 2020 15:54:12 +0200 (CEST) Date: Fri, 24 Jul 2020 15:54:12 +0200 From: Peter Zijlstra To: "Liang, Kan" Cc: acme@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org, jolsa@kernel.org, eranian@google.com, alexander.shishkin@linux.intel.com, ak@linux.intel.com, like.xu@linux.intel.com Subject: Re: [PATCH V7 07/14] perf/core: Add a new PERF_EV_CAP_COEXIST event capability Message-ID: <20200724135412.GA10769@hirez.programming.kicks-ass.net> References: <20200723171117.9918-1-kan.liang@linux.intel.com> <20200723171117.9918-8-kan.liang@linux.intel.com> <20200724105543.GV119549@hirez.programming.kicks-ass.net> <20200724114628.GJ43129@hirez.programming.kicks-ass.net> <0d33a25c-cfe4-af7f-c915-a98dba17b53b@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0d33a25c-cfe4-af7f-c915-a98dba17b53b@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 24, 2020 at 09:43:44AM -0400, Liang, Kan wrote: > > > On 7/24/2020 7:46 AM, peterz@infradead.org wrote: > > On Fri, Jul 24, 2020 at 12:55:43PM +0200, peterz@infradead.org wrote: > > > > + event_sched_out(event, cpuctx, ctx); > > > > + perf_event_set_state(event, PERF_EVENT_STATE_ERROR); > > > > +} > > > > > > Ah, so the problem here is that ERROR is actually recoverable using > > > IOC_ENABLE. We don't want that either. Let me try and figure out of EXIT > > > would work. > > > > EXIT is difficult too.. Also, that COEXIST thing hurt my brian, can't we > > do a simpler SIBLING thing that simply requires the event to be a group > > sibling? > > > > The consequence is that SLOTS must be the leader, is that really a > > problem? You keep providing the {cycles, slots, metric-things} example, > > but afaict {slots, metric-thing, cycles} should work just fine too. > > PERF_SAMPLE_READ with PERF_FORMAT_GROUP doesn't need to the the leader. > > I'm not sure I get your point. > For the PERF_SAMPLE_READ with PERF_FORMAT_GROUP case, other events can be > the leader, e.g., {cycles, slots, metric-things}:S. > In this case, the SLOTS event is not a leader. I don't think we can assume > that the SLOTS event must be the leader. You can have a sibling event with SAMPLE_READ and FORMAT_GROUP just fine. The sampling event doesn't need to be the leader.