From owner-freebsd-net@FreeBSD.ORG Wed Feb 26 21:13:48 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 97EB1B56 for ; Wed, 26 Feb 2014 21:13:48 +0000 (UTC) Received: from nm18-vm4.bullet.mail.ne1.yahoo.com (nm18-vm4.bullet.mail.ne1.yahoo.com [98.138.91.178]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 1F5581C98 for ; Wed, 26 Feb 2014 21:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=gcom1024; t=1393449221; bh=7lpCma4jYsxeRIWPEgxRjMbJCUPiGqQfwxw7+5iJHZY=; h=Received:Received:Received:DKIM-Signature:X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:X-Rocket-Received:Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References:To:X-Mailer; b=XeYplA72BwjUdBOleYSPQcPgvy/140qElgUb5MfwLHcf4ORLqjYAl/rahRTYA6jUgbWaRWrSTVGGF/IZ+0omOdo4gQWnucpWt/RrJCbq947yKWvwxJGYm03jKf2voz78BQXHLqa8KeEcqkAA6tkQ15KnTrcqUg2py6DFxcdGOZk= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=gcom1024; d=yahoo.com; b=A4ViExLBcDFB/oR5KJtpx+7ChsXc0cDWV0lPgx9HWt8lI3Sm9kiJL9jfDSQ5o781x27mNdxTwIaCY2iBQYCUdTyX798oEIZ+MycXp2kfdoGLCSxSjOqkabsFN7M9sSvi14o8i0buigNlsLG6cFMonSnI1AMIaHmLn+jhU5q/BmQ=; Received: from [98.138.100.117] by nm18.bullet.mail.ne1.yahoo.com with NNFMP; 26 Feb 2014 21:13:41 -0000 Received: from [98.138.226.126] by tm108.bullet.mail.ne1.yahoo.com with NNFMP; 26 Feb 2014 21:13:40 -0000 Received: from [127.0.0.1] by smtp205.mail.ne1.yahoo.com with NNFMP; 26 Feb 2014 21:13:40 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1393449220; bh=7lpCma4jYsxeRIWPEgxRjMbJCUPiGqQfwxw7+5iJHZY=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:X-Rocket-Received:Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References:To:X-Mailer; b=sAa4SptRDNFzJ4oCdl/2NXzeAlw0aqtimXeU/T7UfnbIoUQ0Yz1b7ZtKyvXpb2cWyJVmBpNKpA4XL58yfn4t0ZdKpts+5vwegrds1pdtiaY4J0kZKLFBnFfT2FWtffvjw9GqtTroFHcNAvzsbLsSssygqLBgUDOG3zM2KtTCYgU= X-Yahoo-Newman-Id: 922453.9063.bm@smtp205.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: AWoEOqUVM1k.5N8Z5hAbDR6humzhSxzLJxwQSGRCGr1G_5Q 0eLJmqMMh_wmKxRwsokDdwdlUAFwIKo9olLs9TTP6Lchknm1fSm.d2g4o7ht XmFbmT9.05OQAFkOKYXagtvoSzGF4678oXCaBqKbu8N_KyTvevDOkkU7Wfqk 83Vvu8siqctHADzAZICe15JmGT33IVGKT3NYGpaXkhZ.On.HuDZ1T.B0xcFH I5fdPMUcgGK.oikg56zDG1uEy5rtrf8_CxeUwPk_Yj8IrZHJBHebXh9clHCc PGBN3M9iO2s1vMhi_PoZOhRQSBwmVVxV7NzI_U25JSEa.mnYnU2.OX8gtzTQ HlKi_HfVDmEi9JnWgPHiucSOzsTaoFMl8Lk9sqGZVSLLwbL3CYFYP8V90x.o KRgH.FlulPltWG.giOvUcokND3cZpF1NahTQ16sYgvpEjL4E._tQUwi_n5Hw emQ7e4Pk82DDiKRsQOXZFWMKT_BVhNQxMgCjerFgtiFN86Ga.HFCOqu4LcVe 5rWJmiXZk8.OxGUxwI_cM_ExFhSNYvWy6UorznaJRmro_lrwQYoBF1KOhlVE GVbAXTK4y X-Yahoo-SMTP: clhABp.swBB7fs.LwIJpv3jkWgo2NU8- X-Rocket-Received: from lgmac-bvermilion.corp.netflix.com (scott4long@69.53.236.251 with plain [98.139.211.125]) by smtp205.mail.ne1.yahoo.com with SMTP; 26 Feb 2014 13:13:40 -0800 PST Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.1 \(1827\)) Subject: Re: TSO From: Scott Long In-Reply-To: Date: Wed, 26 Feb 2014 13:13:36 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20140226180736.GV92037@funkthat.com> To: Jack Vogel X-Mailer: Apple Mail (2.1827) Cc: FreeBSD Net , Sami Halabi X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Feb 2014 21:13:48 -0000 Are you proposing that the network stack track the physical memory = segment details of the mbufs as they are formed and chained together? Scott On Feb 26, 2014, at 10:27 AM, Jack Vogel wrote: > Drivers have to work with whatever the requirements/limitations of the > hardware, > if you have a 5 lb sack you shouldn't be surprised if some drops when = you > shove > 6 lbs at it :) >=20 > Why not have this limit in the interface so the stack can avoid = exceeding > it? >=20 > Jack >=20 >=20 >=20 >=20 > On Wed, Feb 26, 2014 at 10:07 AM, John-Mark Gurney = wrote: >=20 >> Sami Halabi wrote this message on Wed, Feb 26, 2014 at 19:37 +0200: >>> I'm reading (almost) all mailing emails in mailig list... >>>=20 >>> Almost every / many problem in network performancr / packets loss = ended >> up >>> suggesting disabling TSO. >>>=20 >>> I wonder why.. Is it a bug in the implementation? Or bybdesign? >>> What are the usecases that TSO is needed? Myabe it should be = disabled bt >>> default? >>=20 >> It looks like most of the problems are in drivers that don't handle >> packets with a large number of segments properly... The problem is >> that some drivers limit to how segments a packet can be broken into, = and >> then if they receive such a packet, instead of doing their darnest to >> deliver it, they drop it... >>=20 >> There are some patches that help address the issue... >>=20 >> Drivers should complain more loudly when a packet gets dropped by the >> driver, since it is likely that the OS may retry the same packet, >> just to have it fail, though sometimes it'll try a different set, and >> it might go through, so all the user may notice is a slight lag if >> they notice anything at all... >>=20 >> -- >> John-Mark Gurney Voice: +1 415 225 5579 >>=20 >> "All that I will do, has been done, All that I have, has not." >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to = "freebsd-net-unsubscribe@freebsd.org" >>=20 > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"