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 7F994C433EF for ; Wed, 16 Mar 2022 11:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355293AbiCPLVL (ORCPT ); Wed, 16 Mar 2022 07:21:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348129AbiCPLVJ (ORCPT ); Wed, 16 Mar 2022 07:21:09 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA2F33BF84; Wed, 16 Mar 2022 04:19:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647429595; x=1678965595; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=WOZPX280h/gDeG6eQLXb35wKGPqTHaoiFvqKuqkEwNg=; b=IlYui+VZshSHfhBilyE1Fa5IfIXrFlPbWcYR9NVc+bO1aLJvHUDfGzNz Qv6Ze3Ej9jrNZy/GRKpzOSYO2z35WcfJcxviXeIsoTDXkdeqr9oD91dg2 wx5ViquMl16akcuEUmaouItpssNIXQn2uIo+mti2VxLzxgi1Dpn7ZWd+0 YUj9YHRnl/dWfNEJuQM7V55SUdIGpPGWRnmrI2B03+3xjiwVHPiVEBxAC oKdYum+p/ByteXCsET9QXTkcAeYlOP+MTq8wOxKu4cYSVoyDh6s7yKbEG AydpU2AUdAVvTX+iRT1lRt5/h08CJ/CeEJVPvcWAgbXGpdZRsv6iv5zwA g==; X-IronPort-AV: E=McAfee;i="6200,9189,10286"; a="255383241" X-IronPort-AV: E=Sophos;i="5.90,186,1643702400"; d="scan'208";a="255383241" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2022 04:19:55 -0700 X-IronPort-AV: E=Sophos;i="5.90,186,1643702400"; d="scan'208";a="557392932" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.252.35.28]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2022 04:19:52 -0700 Message-ID: Date: Wed, 16 Mar 2022 13:19:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.5.0 Subject: Re: [PATCH] perf intel-pt: Synthesize cycle events Content-Language: en-US To: "Steinar H. Gunderson" Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220310093844.982656-1-sesse@google.com> <586de5fc-858b-2693-1986-5c77e8c0e3d0@intel.com> <52903e58-e74c-5ea0-36b4-277ea3610af4@intel.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16.3.2022 10.19, Steinar H. Gunderson wrote: > On Tue, Mar 15, 2022 at 10:11:54PM +0200, Adrian Hunter wrote: >> Sorry, my first suggestion has issues, but the second is better. > > I tried your second one, but can't see much difference. The original and > your patched version still differ by a lot, and I still see various > non-branch instructions getting very tiny fractions. (PSB packets > _might_ be it, as there are ~1000 of them in the 165M-cycle trace.) > > I guess the good news is that the perf report coming out of your version > looks more likely to me; I have some functions that are around 1% that > shouldn't intuitively be that much (and, if I write some Perl to sum up > the cycles from the IPC lines in perf script, are more around 0.1%). > So perhaps we should stop chasing the difference? I don't know. That doesn't sound right. I will look at it more closely in the next few days.