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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 96156C56202 for ; Fri, 20 Nov 2020 12:50:14 +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 2009422227 for ; Fri, 20 Nov 2020 12:50:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="URGxCB46" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2009422227 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.32149.63094 (Exim 4.92) (envelope-from ) id 1kg5rV-0005UG-QT; Fri, 20 Nov 2020 12:50:01 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 32149.63094; Fri, 20 Nov 2020 12:50:01 +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" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kg5rV-0005U9-Mx; Fri, 20 Nov 2020 12:50:01 +0000 Received: by outflank-mailman (input) for mailman id 32149; Fri, 20 Nov 2020 12:50:00 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kg5rU-0005U3-Nn for xen-devel@lists.xenproject.org; Fri, 20 Nov 2020 12:50:00 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 0c9d0fa7-3621-4664-bc16-859c2f0339b2; Fri, 20 Nov 2020 12:50:00 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 441FCAC54; Fri, 20 Nov 2020 12:49:59 +0000 (UTC) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kg5rU-0005U3-Nn for xen-devel@lists.xenproject.org; Fri, 20 Nov 2020 12:50:00 +0000 X-Inumbo-ID: 0c9d0fa7-3621-4664-bc16-859c2f0339b2 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 0c9d0fa7-3621-4664-bc16-859c2f0339b2; Fri, 20 Nov 2020 12:50:00 +0000 (UTC) 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=1605876599; 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=t4Hh5f4iDAvskmK3yhQGv4nBpbYLAadWTv9j2Ooxa04=; b=URGxCB46a9ikHNFtOZjqW4jSc+vNs/+HwLIWrZTLk4Z+7uGc4FEFVkjl8Dgu6aubClvETp pieU9oramiW/o+pBBCGRbI51ebK5reHHZngNluLYiI7CpNcLk3ZvpI8W5dP6+1ZHlEv6s0 aaA0cX7BzdkJ+HyzPDk0uv64eX8Kd6w= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 441FCAC54; Fri, 20 Nov 2020 12:49:59 +0000 (UTC) Subject: Ping: [PATCH] gnttab: don't allocate status frame tracking array when "gnttab=max_ver:1" From: Jan Beulich To: Andrew Cooper , George Dunlap , Julien Grall , Stefano Stabellini , Wei Liu Cc: Ian Jackson , "xen-devel@lists.xenproject.org" References: Message-ID: Date: Fri, 20 Nov 2020 13:50:00 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 05.11.2020 16:55, 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. Do so indirectly > though, by making grant_to_status_frames() return zero in this case. > > Signed-off-by: Jan Beulich Ping? > --- a/xen/common/grant_table.c > +++ b/xen/common/grant_table.c > @@ -446,11 +446,14 @@ static inline void active_entry_release( > > static inline unsigned int grant_to_status_frames(unsigned int grant_frames) > { > + if ( opt_gnttab_max_version < 2 ) > + return 0; > return DIV_ROUND_UP(grant_frames * GRANT_PER_PAGE, GRANT_STATUS_PER_PAGE); > } > > static inline unsigned int status_to_grant_frames(unsigned int status_frames) > { > + ASSERT(opt_gnttab_max_version >= 2); > return DIV_ROUND_UP(status_frames * GRANT_STATUS_PER_PAGE, GRANT_PER_PAGE); > } > >