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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 1B63DC742CF for ; Fri, 12 Jul 2019 15:59:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECAE2206B8 for ; Fri, 12 Jul 2019 15:59:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726811AbfGLP74 (ORCPT ); Fri, 12 Jul 2019 11:59:56 -0400 Received: from dispatch1-us1.ppe-hosted.com ([67.231.154.164]:51974 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726992AbfGLP7z (ORCPT ); Fri, 12 Jul 2019 11:59:55 -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-us5.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 376354C0061; Fri, 12 Jul 2019 15:59:54 +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; Fri, 12 Jul 2019 08:59:50 -0700 Subject: Re: [RFC PATCH net-next 0/3] net: batched receive in GRO path To: Eric Dumazet , Paolo Abeni , David Miller CC: netdev References: <7920e85c-439e-0622-46f8-0602cf37e306@solarflare.com> <677040f4-05d1-e664-d24a-5ee2d2edcdbd@solarflare.com> <1735314f-3c6a-45fc-0270-b90cc4d5d6ba@gmail.com> <4516a34a-5a88-88ef-e761-7512dff4f3ce@solarflare.com> <38ff0ce0-7e26-1683-90f0-adc9c0ac9abe@gmail.com> From: Edward Cree Message-ID: <927da9ee-c2fc-8556-fbeb-e26ea1c98d1e@solarflare.com> Date: Fri, 12 Jul 2019 16:59:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <38ff0ce0-7e26-1683-90f0-adc9c0ac9abe@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-GB X-Originating-IP: [10.17.20.203] X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.5.1010-24752.005 X-TM-AS-Result: No-0.793900-4.000000-10 X-TMASE-MatchedRID: zGP2F0O7j/vmLzc6AOD8DfHkpkyUphL9vMRNh9hLjFkN1GharxC4Vh8a RhKglPt8MkD82d8QeUgrnb4nIraZw+q4eBfl/7E8M71h0SMVl8IGchEhVwJY3/pmcjkHZ8l7sVQ jUK5/ysnC4wmUkR7jamggkMcg8tITxnMngDvUy6nvWGhFrXKaNviH64jt3FfED5cyUgWQb9WQ2R P0epqKb+aP62L1S/onX7bicKxRIU2jXmQlwROveWrz/G/ZSbVq+gtHj7OwNO34ZhR52Rc1akmYJ UcmmmV4EcBCAINv3nste9qj8HHZNGBDg9q5BJMbWsXfcuk2iQb1JkrkU09vPuXq904rTlMak0kG S3cR7Ps9Dz34CBgs2IfMZMegLDIeGU0pKnas+RbnCJftFZkZizYJYNFU00e7N+XOQZygrvY= X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--0.793900-4.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.5.1010-24752.005 X-MDID: 1562947194-MOInDFL7mw6C Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/07/2019 18:39, Eric Dumazet wrote: > Holding a small packet in the list up to the point we call busy_poll_stop() > will basically make busypoll non working anymore. > > napi_complete_done() has special behavior when busy polling is active. Yep, I get it now, sorry for being dumb :) Essentially we're saying that things coalesced by GRO are 'bulk' traffic and  can wait around, but the rest is the stuff we're polling for for low latency. I'm putting a gro_normal_list() call after the trace_napi_poll() in  napi_busy_loop() and testing that, let's see how it goes...