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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 7E8AFC433E0 for ; Fri, 5 Jun 2020 01:57:50 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4B6F1207D3 for ; Fri, 5 Jun 2020 01:57:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B6F1207D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55434 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jh1cD-0006PG-Ju for qemu-devel@archiver.kernel.org; Thu, 04 Jun 2020 21:57:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57202) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jh1bi-0005xa-E1 for qemu-devel@nongnu.org; Thu, 04 Jun 2020 21:57:18 -0400 Received: from mga03.intel.com ([134.134.136.65]:47465) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jh1bg-00063U-Ua for qemu-devel@nongnu.org; Thu, 04 Jun 2020 21:57:18 -0400 IronPort-SDR: smHpSY8GqLFdJ8kjYPRdEOX/EHMpa4+68GD06/6IrxJJLvkz2eifD04/i7TGQDRTIESm7X9PhZ yr1mhbQ4Wfew== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2020 18:57:12 -0700 IronPort-SDR: HIXxoyO/PCscPKLBTKn6VPU1cZFQufCvumE5wTrv0vRUbMaa27IsSAw7NXJw4GQKnbToINtAMw 6Th53IT0eeUw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,474,1583222400"; d="scan'208";a="445722546" Received: from unknown (HELO [10.239.13.113]) ([10.239.13.113]) by orsmga005.jf.intel.com with ESMTP; 04 Jun 2020 18:57:08 -0700 Message-ID: <5ED9A81F.6070008@intel.com> Date: Fri, 05 Jun 2020 10:04:15 +0800 From: Wei Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Richard Henderson , "Dr. David Alan Gilbert" Subject: Re: [PATCH v3] migration/xbzrle: add encoding rate References: <1588208375-19556-1-git-send-email-wei.w.wang@intel.com> <5ED86344.4020505@intel.com> <4b9cd244-0d96-d1c8-11ec-b61a6bc2bfaa@linaro.org> <20200604093828.GB2851@work-vm> <5ED8CC78.90006@intel.com> <26a232a7-8ec6-da2c-348f-41da899cdc9a@linaro.org> In-Reply-To: <26a232a7-8ec6-da2c-348f-41da899cdc9a@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=134.134.136.65; envelope-from=wei.w.wang@intel.com; helo=mga03.intel.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/04 21:57:14 X-ACL-Warn: Detected OS = FreeBSD 9.x or newer [fuzzy] X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kevin.tian@intel.com, Juan Quintela , "qemu-devel@nongnu.org Developers" , Peter Xu , gloryxiao@tencent.com, yi.y.sun@intel.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 06/05/2020 12:57 AM, Richard Henderson wrote: > On 6/4/20 3:27 AM, Wei Wang wrote: >> On 06/04/2020 05:38 PM, Dr. David Alan Gilbert wrote: >>> Hmm OK; I'll admit to not liking NaN/Inf in output. >>> >>> Dave >>> >> OK. To deal with the reported issue, how about using FLT_MAX (as opposed to >> UINT64_MAX or inf): >> xbzrle_counters.encoding_rate = FLT_MAX; > So you'd rather see 340282346638528859811704183484516925440.00 printed? > > It's arbitrary and not correct in any mathematical sense. > > If you *really* insist on not printing Inf (which may have some diagnostic > value), then 0 is just as arbitrary, and at least smaller in the output. 0 works fine (though it logically means the lowest encoding rate). I slightly prefer the biggest number or inf, which naturally means it's very encoding friendly. Let's see if Dave has any thought about the choices :) Best, Wei