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=-8.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 87D2DC55178 for ; Thu, 5 Nov 2020 15:55:44 +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 0F0E120782 for ; Thu, 5 Nov 2020 15:55:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="UetZGdAF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F0E120782 Authentication-Results: mail.kernel.org; dmarc=fail (p=none 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.19891.45369 (Exim 4.92) (envelope-from ) id 1kahbo-0005hr-Cv; Thu, 05 Nov 2020 15:55:32 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 19891.45369; Thu, 05 Nov 2020 15:55:32 +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 1kahbo-0005hk-9z; Thu, 05 Nov 2020 15:55:32 +0000 Received: by outflank-mailman (input) for mailman id 19891; Thu, 05 Nov 2020 15:55:31 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kahbn-0005hf-6J for xen-devel@lists.xenproject.org; Thu, 05 Nov 2020 15:55:31 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 34be8d1a-bfad-4516-ad4f-a210cd72ef13; Thu, 05 Nov 2020 15:55:29 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 38A9CAFD0; Thu, 5 Nov 2020 15:55:28 +0000 (UTC) Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kahbn-0005hf-6J for xen-devel@lists.xenproject.org; Thu, 05 Nov 2020 15:55:31 +0000 X-Inumbo-ID: 34be8d1a-bfad-4516-ad4f-a210cd72ef13 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 34be8d1a-bfad-4516-ad4f-a210cd72ef13; Thu, 05 Nov 2020 15:55:29 +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=1604591728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MYdxot3OwZOi0x0Jjwp1g2jZlQ7iqjA0dOj9aslvivg=; b=UetZGdAFKqhOSyq+exNQgpd8MYRvlBcVBhy8UkrYZVPkcJ7Xj63NhNA5gUGUvGLKZN0KRP 8UI509CVPFnFZGuf7QEWmc41kPF22G85wDI7klGGocmhd45xuRIKPFmjMwfebg0Qd+nw+a mXIr/y7mLCjkbOzmZ4N9sXil5RJdkFc= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 38A9CAFD0; Thu, 5 Nov 2020 15:55:28 +0000 (UTC) To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu From: Jan Beulich Subject: [PATCH] gnttab: don't allocate status frame tracking array when "gnttab=max_ver:1" Message-ID: Date: Thu, 5 Nov 2020 16:55:25 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 --- 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); }