From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: Re: [DCCP] [RFC] [Patchv2 1/1]: Queuing policies -- reworked version of Tomasz's patch set Date: Fri, 25 Apr 2008 17:40:24 -0300 Message-ID: <20080425204024.GA16635@ghostprotocols.net> References: <20080421131253.GB12221@ghostprotocols.net> <20080422174152.GD6039@gerrit.erg.abdn.ac.uk> <20080422.154212.108914213.davem@davemloft.net> <200804252133.11264.tomasz@grobelny.oswiecenia.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , gerrit@erg.abdn.ac.uk, dccp@vger.kernel.org, netdev@vger.kernel.org To: Tomasz Grobelny Return-path: Received: from mx1.redhat.com ([66.187.233.31]:34925 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760214AbYDYUkh (ORCPT ); Fri, 25 Apr 2008 16:40:37 -0400 Content-Disposition: inline In-Reply-To: <200804252133.11264.tomasz@grobelny.oswiecenia.net> Sender: netdev-owner@vger.kernel.org List-ID: Em Fri, Apr 25, 2008 at 09:33:11PM +0200, Tomasz Grobelny escreveu: > Dnia Wednesday 23 of April 2008, David Miller napisa=C5=82: > > From: Gerrit Renker > > Date: Tue, 22 Apr 2008 18:41:52 +0100 > > > > > | If we iron this out we could finally return to the main subject= of this > > > | thread. That is Patch v2 by me and Gerrit... > > > | -- > > > > > > Fully agree - we just need to decide whether or not to use skb->p= riority. > > > > > > Below is as far as I got in integrating your patch last week, it = shows > > > only the major changes. The following bits have been updated: > > > > > > * skb->priority now cleared before passing the skb onto layer 3; > > > * order of statements in prio_push() reversed (first dropping wo= rst > > > skb and then pushing the new skb - this is better when e.g. > > > tx_qlen=3D1); > > > * added general parsing routine for cmsg(3) socket control messa= ges > > > and defined one for the SOL_DCCP socket level; thanks to advic= e > > > by Dave Miller > > > > If this usage of skb->priority is going to override the > > IP_TOS socket option setting, I don't think it's a good > > idea. > > > > Right now every packet output goes through ip_output.c > > which sets skb->priority to sk->sk_priority, which is set > > by the user via the IP_TOS socket option in ip_sockglue.c > >=20 > But I guess this assignment happens a bit later (that is after outgoi= ng packet=20 > leaves DCCP code). Consequently using skb->priority should not harm a= s it=20 > will be overwritten. Or did I miss something? I haven't read all the patches, but I guess Tomasz is on the safe side as the intended skb->priority usage is limited to DCCP, when IP is handed the skb it can do as it pleases with skb->priority. - Arnaldo