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 A30FEC77B72 for ; Mon, 17 Apr 2023 11:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbjDQLsP (ORCPT ); Mon, 17 Apr 2023 07:48:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230048AbjDQLsM (ORCPT ); Mon, 17 Apr 2023 07:48:12 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 161961AB for ; Mon, 17 Apr 2023 04:47:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=2sbQzu7RniseVk+khnE2kGEB/bPWNfsL2nxC/lM0Zu0=; b=NXC0G2nchijGyOCEIYYKVhI4/k gECLFsUAU3H7pol0l1kU46JbLboQPhaXylBAd7rInZD95hRQix4LDeSRfaprvhhdQfmHtmLEben3z aC+KN1pwgbBbl4RYF8B94jdJ1SiOnOY7ATr6z48fjTZk1HRAx1hnKifSIAirgXsRuRISJ/zrdANoi atCNiiUdfWpqDVBgtGT0a14OG5MRSeYgF+UGout5J5yFAqQeBbSeiXnN3gU168PIeWGEyWM29eMYs /IA0nIt2mALw6mu2NccAXLF3seKWEzEUlQup7jUcC9WdKDmQ7w3EUyMFChuNMlaRvKBHSWq8CAFr9 5agmYj7w==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1poNJv-00HJ1f-2o; Mon, 17 Apr 2023 11:46:56 +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 682BF300338; Mon, 17 Apr 2023 13:46:54 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4EC8024248739; Mon, 17 Apr 2023 13:46:54 +0200 (CEST) Date: Mon, 17 Apr 2023 13:46:54 +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: <20230417114654.GL83892@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: > > > Yeah, don't do this. There is no guarantee what so ever you'll get any > > of those events in the 0-3 range. > > > The kernel can simply force to 0-3 if LBR is enabled and the feature too. > It's in Kan's patch > > and it isn't particularly complicated. And what, totally leave 4-7 unused even if those counters were not related to LBR at all? That seems exceedingly daft.