From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: Packetlost when "tc qdisc del dev eth0 root" Date: Tue, 15 Jan 2008 17:05:42 +0100 Message-ID: <478CD9D6.3000504@trash.net> References: <478C94B7.3070503@bigtelecom.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Badalian Vyacheslav Return-path: Received: from stinky.trash.net ([213.144.137.162]:43487 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751363AbYAOQFy (ORCPT ); Tue, 15 Jan 2008 11:05:54 -0500 In-Reply-To: <478C94B7.3070503@bigtelecom.ru> Sender: netdev-owner@vger.kernel.org List-ID: Badalian Vyacheslav wrote: > Hello all. Have packetlost when do "tc qdisc del dev eth0 root". > > look: > > slavon ~ # ping -f 87.255.1.134 > PING 87.255.1.134 (87.255.1.134) 56(84) bytes of data. > . > ..................................................................................................................................................................................................................................................................... > > . > --- 87.255.1.134 ping statistics --- > 60811 packets transmitted, 60544 received, 0% packet loss, time 39528ms > rtt min/avg/max/mdev = 0.203/0.579/3227.655/13.124 ms, pipe 219, > ipg/ewma 0.650/2.197 ms > > Its normal? Yes, packets in the old qdisc are lost. > Maybe if tc do changes - need create second queue (hash of rules or how > you named it?) and do changes at it. Then replace old queue rules by > created new. > Logic - > 1. Do snapshot > 2. Do changes in shapshot > 3. All new packets go to snapshot > 4. If old queue not have packets - delete it. > 5. Snapshot its default. That doesn't really work since qdiscs keep internal state that in large parts depends on the packets queued. Take the qlen as a simple example, the new qdisc doesn't know about the packets in the old one and will exceed the limit.