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 13E5FC4361B for ; Fri, 4 Dec 2020 10:02:36 +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 9B0FB22795 for ; Fri, 4 Dec 2020 10:02:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B0FB22795 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com 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.44308.79421 (Exim 4.92) (envelope-from ) id 1kl7ul-0007Xs-Mg; Fri, 04 Dec 2020 10:02:11 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 44308.79421; Fri, 04 Dec 2020 10:02:11 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kl7ul-0007Xl-Jj; Fri, 04 Dec 2020 10:02:11 +0000 Received: by outflank-mailman (input) for mailman id 44308; Fri, 04 Dec 2020 10:02:10 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kl7uk-0007Xg-DJ for xen-devel@lists.xenproject.org; Fri, 04 Dec 2020 10:02:10 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2fb25cac-dc63-4e1c-909b-5931cc4c5452; Fri, 04 Dec 2020 10:02:09 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A9816AFB4; Fri, 4 Dec 2020 10:02:08 +0000 (UTC) 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" X-Inumbo-ID: 2fb25cac-dc63-4e1c-909b-5931cc4c5452 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607076128; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yWdjWukSl+2mN1AWCmKhG0bEjMooLyrm1HRLOc99GTs=; b=T0cs8FczasGJrkUjdPIKLQ+aFXUAAtVp8jUmPvvmjDIA+0dV1NMZkslQPXoibrOQeqaiAS OKsmzla9oCWQcrpfOu2r/j47uHWCf30vuDok1kbfvBsla6CUTLa/WUPCSntB9jHVRt9/sn rwx8Ogwyf2zoOjNrjsN9Mhd7Xhn/rlU= Subject: Re: [PATCH] gnttab: don't allocate status frame tracking array when "gnttab=max_ver:1" To: Julien Grall Cc: Andrew Cooper , George Dunlap , Ian Jackson , Stefano Stabellini , Wei Liu , "xen-devel@lists.xenproject.org" References: From: Jan Beulich Message-ID: <6fb5dd40-d9b8-a3c6-9616-070d5fadb59b@suse.com> Date: Fri, 4 Dec 2020 11:02:09 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 02.12.2020 19:31, Julien Grall wrote: > 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? Hmm, yes, seems possible. Let me give this a try. Jan