Date: Wed, 26 Feb 2014 10:27:59 -0800 From: Jack Vogel <jfvogel@gmail.com> To: Sami Halabi <sodynet1@gmail.com>, FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: TSO Message-ID: <CAFOYbckc8=j1kAU097Y=2UjFS747O49vuWYBDLmxOqXUAOkBhw@mail.gmail.com> In-Reply-To: <20140226180736.GV92037@funkthat.com> References: <CAEW%2BogYVto3rr6LHVsG4rOuyhXt3ZWbH2kWNk-1kAmwDKROEqg@mail.gmail.com> <20140226180736.GV92037@funkthat.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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 :) Why not have this limit in the interface so the stack can avoid exceeding it? Jack On Wed, Feb 26, 2014 at 10:07 AM, John-Mark Gurney <jmg@funkthat.com> wrote: > Sami Halabi wrote this message on Wed, Feb 26, 2014 at 19:37 +0200: > > I'm reading (almost) all mailing emails in mailig list... > > > > Almost every / many problem in network performancr / packets loss ended > up > > suggesting disabling TSO. > > > > 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? > > 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... > > There are some patches that help address the issue... > > 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... > > -- > John-Mark Gurney Voice: +1 415 225 5579 > > "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" >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAFOYbckc8=j1kAU097Y=2UjFS747O49vuWYBDLmxOqXUAOkBhw>