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=-12.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 43961C2D0E4 for ; Tue, 24 Nov 2020 04:11:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C63E2085B for ; Tue, 24 Nov 2020 04:11:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=axis.com header.i=@axis.com header.b="YK2E9EnQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728559AbgKXELa (ORCPT ); Mon, 23 Nov 2020 23:11:30 -0500 Received: from smtp2.axis.com ([195.60.68.18]:25714 "EHLO smtp2.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726039AbgKXELa (ORCPT ); Mon, 23 Nov 2020 23:11:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=axis.com; l=1108; q=dns/txt; s=axis-central1; t=1606191090; x=1637727090; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=Y1f7YDPg9br6ZPfXHfQarLxBdVY9HT3ViTHFbV/Iw/s=; b=YK2E9EnQBzzUyLuphzFodHJDYLcwP2Naxu/GYYjP5sB2empIPJ+LEtYw uHGQOtFA49P2Lgi2WcvHcqnALbHeDFjrveiTccVyAGoVqsQbyFtK1dJ9O f0KTIjBaY42zh7dpPTVuJ3GsY26R7Y8aOEPB5kkOYTi2Ggga1ZMuYOuaA RQnAo9iPM8aQna/+JvAJINZJHDVsTVuUvk3yIu6UTT8b37IOSZxZboVWE gwcXTxv1tg1PGwB0I4GFmM4tifDqHAhJoxQ0Qh0R2YEq8mAF8SOESsqpI 9sMOFax8NgBktvhR+lX2Vf0drFR5Pf2zzvGAD4en60/dlsAj7NVcNXPUJ A==; IronPort-SDR: tMm0+kpSgRj21pcR1+YJE0m8mfSZ2dRN4dtMT8ID1PIhgWj3DrNVD+mS5rrubT4/wXKOz94jwM namRJuqOxehCE15wUqGq6CDUgVNRmvdjEdlBwyiznAoSjl7bS0qvY9AjenX7xu4h6HO4CH8Ly8 s8bqIcL0jVt033k249SNpVmLDcnbDve+p7OAcWENQ4GLcaTnGTesP8UXBhlBen3W5SRXDjXL0g jgizM4CFaTZWy6/ItHYMWr2024gKCTL1eL4XMjjybcGLJW9KelPPdthi49d8uHU2F0342ylDUA g6w= X-IronPort-AV: E=Sophos;i="5.78,365,1599516000"; d="scan'208";a="14822153" Date: Tue, 24 Nov 2020 05:11:27 +0100 From: Vincent Whitchurch To: Jakub Kicinski CC: "peppe.cavallaro@st.com" , "alexandre.torgue@st.com" , "joabreu@synopsys.com" , "davem@davemloft.net" , kernel , "netdev@vger.kernel.org" Subject: Re: [PATCH net] net: stmmac: Use hrtimer for TX coalescing Message-ID: <20201124041127.c3uagg4cguqqvgji@axis.com> References: <20201120150208.6838-1-vincent.whitchurch@axis.com> <20201123164600.434b6a9e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20201123164600.434b6a9e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> User-Agent: NeoMutt/20170113 (1.7.2) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Nov 24, 2020 at 01:46:00AM +0100, Jakub Kicinski wrote: > On Fri, 20 Nov 2020 16:02:08 +0100 Vincent Whitchurch wrote: > > This driver uses a normal timer for TX coalescing, which means that the > > with the default tx-usecs of 1000 microseconds the cleanups actually > > happen 10 ms or more later with HZ=100. This leads to very low > > througput with TCP when bridged to a slow link such as a 4G modem. Fix > > this by using an hrtimer instead. > > > > On my ARM platform with HZ=100 and the default TX coalescing settings > > (tx-frames 25 tx-usecs 1000), with "tc qdisc add dev eth0 root netem > > delay 60ms 40ms rate 50Mbit" run on the server, netperf's TCP_STREAM > > improves from ~5.5 Mbps to ~100 Mbps. > > > > Signed-off-by: Vincent Whitchurch > > Looks perfectly reasonable, but you marked it for net. Do you consider > this to be a bug fix, and need it backported to stable? Otherwise I'd > rather apply it to net-next. No, sorry, I think a backport to stable is unnecessary. It should be fine to apply it to net-next. Thanks.