From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: Re: [RFC v2] mac80211: assign needed_headroom/tailroom for netdevs Date: Mon, 05 May 2008 21:05:15 +0200 Message-ID: <1210014316.4181.14.camel@johannes.berg> References: <1210000923.8245.26.camel@johannes.berg> <1ba2fa240805051015t7dfd3bd2nf7bc2fc1ab9799ca@mail.gmail.com> <1210010254.4181.4.camel@johannes.berg> <20080505.115855.137964071.davem@davemloft.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-Zxl5ijVc3VpdlsXeMeVo" Cc: tomasw-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Miller Return-path: In-Reply-To: <20080505.115855.137964071.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org --=-Zxl5ijVc3VpdlsXeMeVo Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2008-05-05 at 11:58 -0700, David Miller wrote: > From: Johannes Berg > Date: Mon, 05 May 2008 19:57:34 +0200 >=20 > > NETIF_F_FRAGLIST I haven't understood, but it seems to apply mostly for > > IP fragmentation? >=20 > That's right. It's for cards that can do IP fragmentation in > hardware. What does "do IP fragmentation in hardware" mean? ip_output.c says: * This IP datagram is too large to be sent in one piece. Break it up= into * smaller pieces (each of size equal to IP header plus * a block of the data of the original IP data part) that will yet fit= in a * single device frame, and queue such a frame for sending. and later /* Prepare header of the next frame, * before previous one went down. */ so that seems to indicate that if the hardware just sends it all out in the right order it'll be fine. So the point is that the hardware will have to split it up into ethernet frames on the IP boundaries? johannes --=-Zxl5ijVc3VpdlsXeMeVo Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUASB9aaqVg1VMiehFYAQK9Lw/8C0BsKLIAi9536avk69sYJADjF2oI1N0L m6R1zFsn+hEQxyjeQrtWDPxjq5p8CcNS6col4S96nmLbwmLWw2R1KhzMhH9zzkBF v6+bhAF7aYbBiv7kPSJPXB1hyrmwx1SRH0x7cFdZckgu5jJKJjSCxr3eXKhzK3+A wy5QvA534lqGpVs1vWUGx9/nw+bA2ZiFede7tYC/iz8EtvR4GM0E4sZKEX1Fn/k+ zxegYGpbJ2BWeMJ+VXJkfwh2Bl6UyLJmPMrUT/RMrSttiE/AV3cMFXXRa4DMheDz VsLiJIwjle3e+OLM640bFY91t3Uhw/2g3+p2WhX+rtWySFEl/BSAtgMo+35xCR56 BdGkIxSbm+o0vc9el7gHePgAPJjBvLHQWnl24vC0ZR+hMHDonN2uTZJMa2dD+ODI UQrT95uolewHcvkoQr9tvx/g3YshBZT/pzjilYnQydDbtj6MAb2h7L/9gDHafSDy Kevgnm24UwJr5HNuDakKqHW5G2IgizeCWa3/osIYeZWPCXJ7c0orl9BK4no74yL8 qsxARKFnSYwZ/KevSeh+qO73Do04Gjkhm7kNDu8eqyhKElPvkznBojwbzqIOwDe2 JyhJ7AdUcvzNYfARBjvk1zAAJcP2wqfekXLhBydqTZaNqEBqAEfB65SW8ykzsTKE Ofr4m4xm0VQ= =Mqqs -----END PGP SIGNATURE----- --=-Zxl5ijVc3VpdlsXeMeVo-- -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html