From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: RE: [PATCH] IPROUTE: Modify tc for new PRIO multiqueue behavior Date: Tue, 08 May 2007 09:28:37 -0400 Message-ID: <1178630917.4078.46.camel@localhost> References: <1178313748.7408.41.camel@johannes.berg> <1178616837.3385.85.camel@debian.sh.intel.com> <1178617538.18162.54.camel@johannes.berg> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Zhu Yi , "Waskiewicz Jr, Peter P" , Stephen Hemminger , Patrick McHardy , netdev@vger.kernel.org, jgarzik@pobox.com, cramerj , "Kok, Auke-jan H" , "Leech, Christopher" , davem@davemloft.net To: Johannes Berg Return-path: Received: from wx-out-0506.google.com ([66.249.82.238]:38765 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934738AbXEHN2s (ORCPT ); Tue, 8 May 2007 09:28:48 -0400 Received: by wx-out-0506.google.com with SMTP id h31so1721976wxd for ; Tue, 08 May 2007 06:28:47 -0700 (PDT) In-Reply-To: <1178617538.18162.54.camel@johannes.berg> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 2007-08-05 at 11:45 +0200, Johannes Berg wrote: .. Sorry, I missed a lot of the discussions; I am busyed out and will try to catchup later tonight. I have quickly scanned the emails and I will respond backwards (typically the most effective way to catchup with a thread). As a summary, I am not against the concept of addressing per-ring flow control. Having said that, i fully understand where DaveM and Stephen are coming from. Making such huge changes to a critical region to support uncommon hardware doesnt abide to the "optimize for the common" paradigm. That is also the basis of my arguement all along. I also agree it is quiet fscked an approach to have the virtual flow control. I think it is driven by some marketing people and i dont really think there is a science behind it. Switched (External) PCI-E which is supposed to be really cheap and hit the market RSN has per-virtual queue flow control, so that maybe where that came from. In any case, that is a digression. Peter, can we meet the goals you strive for and stick to the "optimize for the common"? How willing are you to change directions to achieve those goals? > On Tue, 2007-05-08 at 17:33 +0800, Zhu Yi wrote: > > > Jamal, as you said, the wireless subsystem uses an interim workaround > > (the extra netdev approach) to achieve hardware packets scheduling. But > > with Peter's patch, the wireless stack doesn't need the workaround > > anymore. This is the actual fix. > I dont believe wireless needs anything other than the simple approach i described. The fact that there an occasional low prio packet may endup going out first before a high prio due to the contention is non-affecting to the overall results. > Actually, we still need multiple devices for virtual devices? Or which > multiple devices are you talking about here? > Those virtual devices you have right now. They are a hack that needs to go at some point. cheers, jamal