Date: Sun, 25 Feb 2007 23:25:30 -0800 From: "Jack Vogel" <jfvogel@gmail.com> To: "Kip Macy" <kip.macy@gmail.com> Cc: freebsd-net <freebsd-net@freebsd.org>, Andre Oppermann <andre@freebsd.org> Subject: Re: improved TSO interface needed Message-ID: <2a41acea0702252325k4ec64d59m95a63bebaf6ea30c@mail.gmail.com> In-Reply-To: <b1fa29170702252110h3217bf82pdc9a3b46561b1671@mail.gmail.com> References: <b1fa29170702242255i323077e8t3e5cfe696431c50b@mail.gmail.com> <45E19B54.9060007@freebsd.org> <b1fa29170702250641w3b365a97u62f066087d1bffe8@mail.gmail.com> <45E1A3B4.7090002@freebsd.org> <2a41acea0702252053v2357b5f5tefbcf58375be1a2f@mail.gmail.com> <b1fa29170702252110h3217bf82pdc9a3b46561b1671@mail.gmail.com>
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On 2/25/07, Kip Macy <kip.macy@gmail.com> wrote: > > The stack will send down chains where pkthdr.len > 65536 bytes - I'm > also seeing it send down mbuf chains of 66 mbufs or more. I don't > think all cards can handle an arbitrary number of descriptors being > used for a single packet. 64K is the max, and I believe that is taking into account the headers. What size are you seeing that is larger? Even if an mbuf chain comes down that large, it does NOT form a single packet, it is packetized by the hardware into MTU size, as I said, on the wire, ie as the receiver sees it, its just a lot of packets. The only question is whether the transmit hardware can handle it. Do you have eivdence of some hardware that supports TSO in the driver that cant?? Jack
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