From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.toke.dk (mail.toke.dk [IPv6:2001:470:dc45:1000::1]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id C12953BA8E for ; Wed, 25 Jul 2018 18:13:03 -0400 (EDT) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1532556782; bh=AiYEgzfeAuKYjf4PZnygf+O/ggufOSnXG5fh3ECg9mo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=hFSrj9zLxyHodOMl9Shsqwd+88MWf3NdWickLjBuCDBrDod+X5C24zT7oyzVnyJT2 LgDdaP6pDwFinUMDUUDTkkMeCYWH4UyNo+Z/Wrj0ckkQXn4ZXxzvi29S6hwN7Ky95V 5H+6YPIZIKgaLIlZCLS1U5gI1XvY+rLWzBair8549L8dyIfEaWd5yRoyYGbqpuFcPR eVpOK2vr/ZD+fSW7gAa70MFuDux5MRRH+qZ6RvlQsTjQDJ3wGI+dWGNQNHG4rVGuoH vIymew3Ve4jwf6BXeUaQkdUWqaZxVTkpRyhShKsaY+jJgNGBvr+fOICGniEJ5HYyNe hcTknBC/t7CkQ== To: Dave Taht , Sebastian Moeller Cc: Cake List In-Reply-To: References: <87effr3a72.fsf@toke.dk> <6495D4D7-0920-43C7-A92E-3027102E723D@gmx.de> Date: Thu, 26 Jul 2018 00:12:51 +0200 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <8736w72cd8.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] making split_gso_threshold configurable X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jul 2018 22:13:03 -0000 Dave Taht writes: > On Wed, Jul 25, 2018 at 3:07 AM Sebastian Moeller wrote: >> >> Hi Toke, >> >> >> > On Jul 25, 2018, at 12:02, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> > >> > Dave Taht writes: >> > >> >> I really wanted cake to always optimize for low latency. I wanted it >> >> to "just work" at line rate on dsl, on 100mbit, even 10mbit ethernet, >> >> to work against pause frames, etc, without configuration. I wanted to >> >> defeat drivers like the mvneta that can do 64k of software GRO >> >> automagically. >> > >> > So I think that Eric's point was that the GSO logic itself should >> > throttle back and not build so big packets when the link rate is lower. >> > Might be worth it to check if this is actually the case, and if not to >> > get GSO fixed rather than disabling it. > > It doesn't and I think I should just put forth the patch and face the > howling from the 40gbit guys. Well, feel free I guess? :) >> > Also, are there actually any modems that will negotiate ethernet line >> > rates less than a gigabit? >> >> Yes, there are XDSL Modem(routers) that only have >> fast-ethernet ports. Not sure how rare these are though. > > And there are also many devices that ecert hardware flow control. But why would you ever run with such a device in a setup where flow control gets a chance to kick in? Wouldn't you turn on the shaper anyway (in which case you already get GSO splitting)? -Toke