From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:39633 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762766AbYEHWLL (ORCPT ); Thu, 8 May 2008 18:11:11 -0400 Subject: Re: iwlwifi and tx info in skb->cb From: Johannes Berg To: Tomas Winkler Cc: Ron Rindjunsky , linux-wireless In-Reply-To: <1ba2fa240805081507j7cf991ffo5bae443b0b77a39e@mail.gmail.com> (sfid-20080509_000624_162294_5A80849B) References: <1210197711.3547.1.camel@johannes.berg> <1ba2fa240805071629i6c7336f6y61a7c9690820ef5e@mail.gmail.com> <1210203054.3547.12.camel@johannes.berg> <1ba2fa240805071721i3d1e3258s1e8c024c4cae9239@mail.gmail.com> <1210255522.3547.48.camel@johannes.berg> <1ba2fa240805081507j7cf991ffo5bae443b0b77a39e@mail.gmail.com> (sfid-20080509_000624_162294_5A80849B) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-ObmSmRyRb0L251KCmTE4" Date: Fri, 09 May 2008 00:10:56 +0200 Message-Id: <1210284656.3547.76.camel@johannes.berg> (sfid-20080509_001007_903840_EE924F56) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-ObmSmRyRb0L251KCmTE4 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > > > Currently we actively use 2 of them. First for TX command second for > > > actual frame. It would be even worth if we need to expand > > > each packet also for TX command. > > > > We will no longer do that after davem and I figure out those allocatio= n > > patches. >=20 > Not sure these things are connected. TX command is allocated fixed for ea= ch TFD. Ah, no, I misread that. Well, I think it might still help to say you need N bytes headroom and use those since you wouldn't have to allocate an extra skb. > > You should implement TCP checksumming in the hardware. *that* would he= lp > > a lot. >=20 > There is already pretty much deal of link layer in software to reduce > the cost and the complexity of the HW for these softmac NICs so > this would be kind of strange investment...but I didn't invest much > thoughts into yet. > There are probably other means to utilize scatter gather DMA then TCP > off loading. Are they any other source of scattered packets maybe > iovec? Well as far as I know those too would be zero-copy IO which only works if you have TCP checksumming in hardware. johannes --=-ObmSmRyRb0L251KCmTE4 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUASCN6b6Vg1VMiehFYAQKv+Q//U2o2IF2BFWvx6KizALx9ueo3ZoelKcqq 9xLDgwxqjTWhUdgPkOMEp57tHKX4XK9UAybVou57sHk19bE1fM55bHtJ3h+YIuUU F5Iev8yH79oGG7EjzAAG/9+fSli8+2pcdNBz5ES+rrc8d2wa/nN9TJKDlHOg6JTY DeHe3Z5HxDmuD0TfXNirrClJ4xEDSOKZL7BMo2R57B7aZ4Y8dDtoJTXchGxbfCpv TaY1Zr1R/EXtKEw+lBd6qbXBcY0klRhcZWMVIr8gZ+oqnNgJe6M6IGb+ndgBzjgF kTgwim3jLWnzBbKnrcXpybMUjGIkt8gV0rCrS+vn8ak2pREUte3PRQ7nCnOvm8wd KdfiSKBm7tIp+dEB13dtOk4QLUVxpASr9aB+oIbo1JqFQxf/0fCHYLQBEDHXOVjQ mNmFOKpJYKyY+PU+FbOIK+dd5xnYzJQOObJ50N9EQk0VlmlCr9ZJVlS5kQ0em8ro QmyaNyvFAl30iYVZOayxLita5AWipn6U2o4IC+GSTSOAf6o45ntcDl4C5L1lgWnW 1v4I9MhciHAnuFnRa2PSSIkWcSueahFE1Y6agtamlnSfiUCLHIEHXBbaQjXX0XHp DvmsLA6mbPLoGzN+kWKx6rSwF6vetWSlsW05ze6YzXp/4zqbrqfH9n+aoTAo57yF CJdD5cVECh8= =1Eu+ -----END PGP SIGNATURE----- --=-ObmSmRyRb0L251KCmTE4--