From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from wa-out-1112.google.com ([209.85.146.181]:34078 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558AbYEHW2p (ORCPT ); Thu, 8 May 2008 18:28:45 -0400 Received: by wa-out-1112.google.com with SMTP id j37so1387604waf.23 for ; Thu, 08 May 2008 15:28:44 -0700 (PDT) Message-ID: <1ba2fa240805081528t45d7810cjfd553bf99daff096@mail.gmail.com> (sfid-20080509_002742_123936_376DB97F) Date: Fri, 9 May 2008 01:28:44 +0300 From: "Tomas Winkler" To: "Johannes Berg" Subject: Re: iwlwifi and tx info in skb->cb Cc: "Ron Rindjunsky" , linux-wireless In-Reply-To: <1210284656.3547.76.camel@johannes.berg> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 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> <1210284656.3547.76.camel@johannes.berg> Sender: linux-wireless-owner@vger.kernel.org List-ID: > 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. There actually might be a benefit in doing this but it is quite a change in design which means not now. > > > > You should implement TCP checksumming in the hardware. *that* would help > > > a lot. > > > > 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. I've just scanned the thread that was explaining why is this necessary I will read it more carefully... I have just feeling that all this wlan stuff just fits very awkwardly into current networking stack. Tomas