From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH 00/14]: Killing qdisc->ops->requeue(). Date: Tue, 14 Oct 2008 19:56:49 +0200 Message-ID: <20081014175649.GA2548@ami.dom.local> References: <48F4915D.8000004@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , netdev@vger.kernel.org To: Patrick McHardy Return-path: Received: from ug-out-1314.google.com ([66.249.92.168]:11699 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750812AbYJNR4Q (ORCPT ); Tue, 14 Oct 2008 13:56:16 -0400 Received: by ug-out-1314.google.com with SMTP id k3so1004361ugf.37 for ; Tue, 14 Oct 2008 10:56:13 -0700 (PDT) Content-Disposition: inline In-Reply-To: <48F4915D.8000004@trash.net> Sender: netdev-owner@vger.kernel.org List-ID: David, I acknowledge Patrick's concerns, so please, consider this patch-set as withdrawn. Thanks. A little comment below: Patrick McHardy wrote, On 10/14/2008 02:32 PM: > Jarek Poplawski wrote: ... > I'm sorry for any wasted effort, I think I mentioned this one or > two month ago, but wasn't able to further participate in the > discussion because I was busy with other things. No problem, it seems I missed your point. >> Alas, I can't analyze your concerns at the moment, and I'll try to >> reply in the evening yet, but my idea was this all shouldn't make >> (almost) any visible change just for HFSC, so if it's otherwise, >> something went wrong. IMHO, with this solution hfsc_requeue() way is >> simply realized as a standard now, but I can miss something. > > The main difference results from the fact that higher priority > packets can't preempt "peeked" lower priority packets anymore. > The difference this causes obviously depends on the bandwidth, > but in my opinion the impact (as mentioned. 12ms delay for > 1500b, 1mbit, rises linearly with bigger packets/less bandwidth) > is large enough to speak against these changes. Actually, I think I had similar doubts one or two months ago, but I can remember mainly your discussion on peek with Herbert, and not much about something like above, but probably I didn't pay enough attention. Anyway, the main source of my misleading seems to be HFSC... So do you mean it's OK to use this kind of requeuing in hfsc_requeue(), but not elsewhere? Maybe I miss something, but if some other qdisc is used as a parent of HFSC, and does something like qdisc_peek_len(), it gets just what you're against above? Anyway, I'm glad you've found some time for these explanations, especially since they're in accordance with my previous suspicions. Thanks again, Jarek P.