[{"id":1764294,"web_url":"http://patchwork.ozlabs.org/comment/1764294/","msgid":"<1504720895.15310.69.camel@edumazet-glaptop3.roam.corp.google.com>","list_archive_url":null,"date":"2017-09-06T18:01:35","subject":"Re: [PATCH net-next RFC 2/2] tun: enable napi_gro_frags() for\n\tTUN/TAP driver","submitter":{"id":2404,"url":"http://patchwork.ozlabs.org/api/people/2404/","name":"Eric Dumazet","email":"eric.dumazet@gmail.com"},"content":"On Tue, 2017-09-05 at 15:35 -0700, Petar Penkov wrote:\n> Add a TUN/TAP receive mode that exercises the napi_gro_frags()\n> interface. This mode is available only in TAP mode, as the interface\n> expects packets with Ethernet headers.\n> \n\n\nHi Petar, thanks a lot for this work.\n\nI must confess I have to retract one feedback I gave while reviewing\nyour patches.\n\n\n> +\t\tlocal_bh_disable();\n> +\t\tdata = napi_alloc_frag(fragsz);\n> +\t\tlocal_bh_enable();\n> +\t\tif (!data) {\n> +\t\t\terr = -ENOMEM;\n> +\t\t\tgoto free;\n> +\t\t}\n> +\n> +\t\tpage = virt_to_page(data);\n> +\t\toffset = offset_in_page(data);\n\nThese two lines above indeed trigger too many problems in the kernel.\n(Like the one you tried to cover here\nhttps://patchwork.kernel.org/patch/9927927/ )\n\nPlease use for your next submission the code you originally had :\n\n\tpage = virt_to_head_page(data);\n\toffset = data - page_address(page);\n\n\nThanks !","headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=gmail.com header.i=@gmail.com\n\theader.b=\"NAWtHpyZ\"; dkim-atps=neutral"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xnWcP2QHFz9sBW\n\tfor ;\n\tThu, 7 Sep 2017 04:01:41 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1751836AbdIFSBj (ORCPT );\n\tWed, 6 Sep 2017 14:01:39 -0400","from mail-pf0-f194.google.com ([209.85.192.194]:34693 \"EHLO\n\tmail-pf0-f194.google.com\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1750980AbdIFSBi (ORCPT\n\t); Wed, 6 Sep 2017 14:01:38 -0400","by mail-pf0-f194.google.com with SMTP id y68so3372975pfd.1\n\tfor ; Wed, 06 Sep 2017 11:01:37 -0700 (PDT)","from ?IPv6:2620:15c:2c1:100:71d2:2db4:a10e:204e?\n\t([2620:15c:2c1:100:71d2:2db4:a10e:204e])\n\tby smtp.googlemail.com with ESMTPSA id\n\tw7sm600025pfb.124.2017.09.06.11.01.36\n\t(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);\n\tWed, 06 Sep 2017 11:01:36 -0700 (PDT)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=gmail.com; s=20161025;\n\th=message-id:subject:from:to:cc:date:in-reply-to:references\n\t:mime-version:content-transfer-encoding;\n\tbh=aprcUJAM/NfCvJ/OjYQSffX6Ap/MLPJb+GJR2v6dNhQ=;\n\tb=NAWtHpyZpe+uqdQnRsKqFKn1wT7yYlfQJX/8tUi/gWZ0J224nCnbJZZD5gicBKZPJ+\n\t8EBW5TpftkzLG2SB6rbkmG4WIbjsLgEVhkoHwAmxZZREe2AuqBQ9iz8Q0ICMbHjLzc89\n\tL/ubl4FjNZesm9013PRRwoQa0Hx7Zu2A9S1AYMu39yaoeD6rClzCud6Mv4ietc54iqkU\n\t/1/5gdXEX6OE8OxHXPpeLR7LR6fEvKWH6ZGWtQmdYU9AQcDfbL4t9SDKotwPn4/ZVBjT\n\tjw4WmGAvUkUQdyA+IUenccnzaKS4cZUZ6cVYCaSgYjwlLqHRwxAesFfJ0qWgqFiY5wTW\n\toVPg==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to\n\t:references:mime-version:content-transfer-encoding;\n\tbh=aprcUJAM/NfCvJ/OjYQSffX6Ap/MLPJb+GJR2v6dNhQ=;\n\tb=A7wpLd/ESx1cWYi7VCbq55FYHyqsk7MjtMiW3xnsWWAktcGZlN1NPFGQU0owvW/Pi1\n\tL/S4AUUqkSeQ85nVjdzV3oVK2WrZeemD6qLAdXUM19ELIu9eTyBz/UysR7xYeEgygJCi\n\tRdNsoN2IAkXuKL81tQdfVqybL9V0rzVyzzoF91R28mZsNyFhhxCh/nosr1qPbmewfC86\n\t2XCZx3vCNiEJn/d9OLWVGhjBOR9Lk8GyMzsyYHl88wKMVKlQaXqBrokmVrUtON2MovlI\n\tWMVXP0/n7kbgonmr5FeCtAEpse2cmBk/VqqGauiuiWjPl9Hi1cZsjYhgzyT2PV+pflvL\n\trUuw==","X-Gm-Message-State":"AHPjjUiqw+EH7RRrLFKTMiq8CA8OEXN/AaFTefRKHI1C2QVd73BZHKvN\n\txIYG0QXrAVg2uA==","X-Google-Smtp-Source":"ADKCNb7m44RmN885lRZA96t7LjrsUCny1PlL4fYhK/PSBvvmzO3nqNMQl5++4C3/q2UK84Ks9b22Dw==","X-Received":"by 10.84.209.134 with SMTP id y6mr9174070plh.339.1504720897393; \n\tWed, 06 Sep 2017 11:01:37 -0700 (PDT)","Message-ID":"<1504720895.15310.69.camel@edumazet-glaptop3.roam.corp.google.com>","Subject":"Re: [PATCH net-next RFC 2/2] tun: enable napi_gro_frags() for\n\tTUN/TAP driver","From":"Eric Dumazet ","To":"Petar Penkov ","Cc":"netdev@vger.kernel.org, Eric Dumazet ,\n\tMahesh Bandewar ,\n\tWillem de Bruijn , davem@davemloft.net,\n\tppenkov@stanford.edu","Date":"Wed, 06 Sep 2017 11:01:35 -0700","In-Reply-To":"<20170905223551.27925-3-ppenkov@google.com>","References":"<20170905223551.27925-1-ppenkov@google.com>\n\t<20170905223551.27925-3-ppenkov@google.com>","Content-Type":"text/plain; charset=\"UTF-8\"","X-Mailer":"Evolution 3.10.4-0ubuntu2 ","Mime-Version":"1.0","Content-Transfer-Encoding":"7bit","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"}}]