From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Denys" Subject: Re: iproute2-2.6.20-070313 bug ? Date: Thu, 22 Mar 2007 15:26:12 +0200 Message-ID: <20070322132021.M7074@visp.net.lb> References: <20070321175951.M73913@visp.net.lb> <46026717.9060909@trash.net> <20070322124533.M79867@visp.net.lb> <46027FF2.6020001@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Cc: netdev@vger.kernel.org, Stephen Hemminger To: Patrick McHardy Return-path: Received: from usermail.globalproof.net ([194.146.153.18]:38018 "EHLO usermail.globalproof.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861AbXCVN0a (ORCPT ); Thu, 22 Mar 2007 09:26:30 -0400 In-Reply-To: <46027FF2.6020001@trash.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Dear sir Sorry, i forgot to CC other members of discussion. 1024kb (if i am not wrong 1Mbyte) is huge? For me it is ok, as soon as i have RAM. Another thing, it is working well with old tc. Just really if i have plenty of RAM's and i want 32second buffer, why i cannot have that, and if i see it is really possible before? Possible i am misunderstanding something... In real world i am seeing reasonable to have much bigger buffers, especially if there is no problem in resources (RAM, timer resolution, CPU). For example, as i remember we had failure on one of our STM-1, and Cisco's on Teleglobe was buffering about 20-30seconds of data without major packetloss. Another thing, why i was using buffer, and possible i use it wrong: For example customer have 128Kbit/s account, and i want to give him burst to open web-pages fast (256Kbit/s), but if he use bandwidth non-stop, he will pass this buffer, and will be throttled back to 128Kbit/s. Now seems i cannot give such functionality. On Thu, 22 Mar 2007 14:09:06 +0100, Patrick McHardy wrote > Denys wrote: > > /sbin/tc2 qdisc del dev ppp0 root > > /sbin/tc2 qdisc add dev ppp0 root handle 1: prio > > /sbin/tc2 qdisc add dev ppp0 parent 1:1 handle 2: tbf buffer 1024kb latency > > 500ms rate 128kbit peakrate 256kbit minburst 16384 > > /sbin/tc2 filter add dev ppp0 parent 1:0 protocol ip prio 10 u32 match ip dst > > 0.0.0.0/0 flowid 2:1 > > That is an incredible huge buffer value. > > > qdisc tbf 2: parent 1:1 rate 128000bit burst 4294932937b peakrate > 256000bit minburst 16Kb lat 4.2s > > And it causes an overflow. > > The limit for the TBF burst value with nanosecond resolution is > ~ 4 * rate (10^9 * burst / rate < 2^32 needs to hold), resoluting > in a worst-case latency of 4 seconds. I think this limit is in the > reasonable range. Your configuration results in a worst-case > queuing delay of 64s, and I doubt that you really want that. > > Obviously its not good to break existing configurations, but I > would argue that this configuration is broken. -- Virtual ISP S.A.L.