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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 C3D1FC4360F for ; Mon, 1 Apr 2019 17:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D6F420830 for ; Mon, 1 Apr 2019 17:47:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733309AbfDARbt (ORCPT ); Mon, 1 Apr 2019 13:31:49 -0400 Received: from dispatch1-us1.ppe-hosted.com ([148.163.129.52]:59798 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733095AbfDARbr (ORCPT ); Mon, 1 Apr 2019 13:31:47 -0400 X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (webmail.solarflare.com [12.187.104.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (Proofpoint Essentials ESMTP Server) with ESMTPS id 703301000AD; Mon, 1 Apr 2019 17:31:45 +0000 (UTC) Received: from [10.17.20.203] (10.17.20.203) by ocex03.SolarFlarecom.com (10.20.40.36) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 1 Apr 2019 10:31:40 -0700 Subject: Re: [PATCH net-next] r8169: use netif_receive_skb_list batching To: David Miller , CC: , , , References: <20190331.111114.1510038068515936853.davem@davemloft.net> <61e68943-fb2c-ff89-90e6-1d2742c56687@gmail.com> <20190401.101419.1397780796470309064.davem@davemloft.net> From: Edward Cree Message-ID: Date: Mon, 1 Apr 2019 18:31:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <20190401.101419.1397780796470309064.davem@davemloft.net> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-GB X-Originating-IP: [10.17.20.203] X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.5.1010-24524.005 X-TM-AS-Result: No-3.792100-4.000000-10 X-TMASE-MatchedRID: 7ySqCuYCpfgOwH4pD14DsPHkpkyUphL9+WzVGPiSY8jDTXM3VzSaIhlN xiPQSlnnX5eYBvpYYDEPW5wQsFsruy0kxsNYPyne4aieqCznPEHm3bh+5GLpPMicqvB+icULqmf P5dyxqBUgYsU8L2jyLJGTpe1iiCJq71zr0FZRMbDlOKNhtZF/QlwC6BHzdWkCUEhWy9W70AF5zd Azex5xZigPDiw9JFc6Od/dFHUz/UwJ8qHmrIp3/9IbovsGZZssWTr7f6eT18yUTGVAhB5EbQ== X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--3.792100-4.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.5.1010-24524.005 X-MDID: 1554139906-0ErW5_X_wfS8 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 01/04/2019 18:14, David Miller wrote: > From: Eric Dumazet > Date: Mon, 1 Apr 2019 02:17:12 -0700 > >> This means no GRO at all > I do not think that is true as the SKB list layer does queue up to > GRO. No, Eric is right; the current list layer bypasses GRO completely. netif_receive_skb_list() ends up doing the same things netif_receive_skb() would do on each SKB in the list, and that does not include GRO. (For this reason the sfc driver only uses netif_receive_skb_list() for non-TCP packets; TCP packets go to napi_gro_frags().) I had a patch series to add napi_gro_receive_list() which would use the SKB list layer to handle the packets GRO didn't coalesce ([1]) but the performance tests I ran were inconclusive and it never got applied. -Ed [1]: https://marc.info/?l=linux-netdev&m=154221888012410&w=2