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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 3E33AC71155 for ; Wed, 2 Dec 2020 18:31:54 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 A788222248 for ; Wed, 2 Dec 2020 18:31:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A788222248 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.42965.77316 (Exim 4.92) (envelope-from ) id 1kkWug-0002p5-A3; Wed, 02 Dec 2020 18:31:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 42965.77316; Wed, 02 Dec 2020 18:31:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kkWug-0002oy-71; Wed, 02 Dec 2020 18:31:38 +0000 Received: by outflank-mailman (input) for mailman id 42965; Wed, 02 Dec 2020 18:31:36 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kkWue-0002ot-Cm for xen-devel@lists.xenproject.org; Wed, 02 Dec 2020 18:31:36 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kkWub-0000Fq-R9; Wed, 02 Dec 2020 18:31:33 +0000 Received: from [54.239.6.186] (helo=a483e7b01a66.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1kkWub-0008CU-8Y; Wed, 02 Dec 2020 18:31:33 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject; bh=QWNtZF+8sKsnsiW8NH+OMTwZIn6A98UV+A8Bdjuh28U=; b=HsWiNJVpjjeV45bWsoVRj+l5GB gHuHisQEdUVwxQ30CAa49+YOO3H8YEL19iZXJWCTKw2mA/XbRZQl1/TQdfSWdjSzGlDucRMLF+/dN Kg3QjKhENLaKebKg6Ufhr6oA2P0Ib4ArZA+mtdwQQGAGfnSWZDajo2Un6ym3F5Fde9PU=; Subject: Re: [PATCH] gnttab: don't allocate status frame tracking array when "gnttab=max_ver:1" To: Jan Beulich , "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , George Dunlap , Ian Jackson , Stefano Stabellini , Wei Liu References: From: Julien Grall Message-ID: Date: Wed, 2 Dec 2020 18:31:31 +0000 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Hi Jan, On 05/11/2020 15:55, Jan Beulich wrote: > This array can be large when many grant frames are permitted; avoid > allocating it when it's not going to be used anyway. Given there are not many users of grant-table v2, would it make sense to avoid allocating the array until the guest start using grant-table v2? Cheers, -- Julien Grall