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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D3B9C77B70 for ; Mon, 17 Apr 2023 11:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229889AbjDQL4t (ORCPT ); Mon, 17 Apr 2023 07:56:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230137AbjDQL4p (ORCPT ); Mon, 17 Apr 2023 07:56:45 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A2AB8682 for ; Mon, 17 Apr 2023 04:55:43 -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=gP0S443LaMj7TRidv8xgYhysgY7/1wengzxzodpEXA0=; b=qziPfpA3Y9O59o/xz1qK81ipUU UThDRsiwDtXtjDOtLekqDzS6d0g6a3UnfvH2hhGP560b93jDPqUoCyID5T9I0QOENuUKpH28gj+mr v2eVQu6EHRRIocYZFgpIXroereG6+nt7/iZCHbfrJ1ymxxeWOJjD6j3iq1q8IX7IZSZkVgdEhnQ96 a5UwkOCMFo4ejSGNWGc0MeWY6Aqu3K3TprN5jV+/+/pPBeJ31ynSSDjJiBWfY+BeqiuGGlj3X8tXN F/kczLzrHgqvhTT4DfMSfy4yyYwvYHIlv28ahIUzYNUJPjxVcQjP13vRt4inagAyMj4vs+9qNMDhB sZbw9s6Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1poNS1-00BJML-2J; Mon, 17 Apr 2023 11:55:17 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 85EDF3002A3; Mon, 17 Apr 2023 13:55:16 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 68C9324248708; Mon, 17 Apr 2023 13:55:16 +0200 (CEST) Date: Mon, 17 Apr 2023 13:55:16 +0200 From: Peter Zijlstra To: Andi Kleen Cc: "Liang, Kan" , mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, eranian@google.com Subject: Re: [PATCH 2/6] perf: Support branch events logging Message-ID: <20230417115516.GM83892@hirez.programming.kicks-ass.net> References: <20230414103832.GD83892@hirez.programming.kicks-ass.net> <1d62b865-5d31-ec36-99e0-785844f79199@linux.intel.com> <20230414145324.GB761523@hirez.programming.kicks-ass.net> <803927bb-6f74-5c09-3c18-2fd5f423287b@linux.intel.com> <20230414160945.GC761523@hirez.programming.kicks-ass.net> <085fa11e-ea07-c148-1b32-8a09007ee12b@linux.intel.com> <20230414192407.GA778423@hirez.programming.kicks-ass.net> <2428e6a2-9578-1e1d-bdef-ffcc87301503@linux.intel.com> <20230414220106.GC778423@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 14, 2023 at 03:47:29PM -0700, Andi Kleen wrote: > > You really *must* make then a group such that perf knows what events to > > associated with the LBR event and constain them to the 0-3 range of > > PMCs. > > > > If you want multiplexing, simply create multiple groups with an LBR > > event in them. > > > Well if you force groups then you require user space or a user which > understands all the constraints The LBR feature is naturally a group read, very similar to PERF_SAMPLE_READ+PERF_FORMAT_GROUP. > to create groups. I thought one of the basic ideas of perf was to be able to > abstract those things. Yeah, the abstraction at hand is a group.