From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] [RESEND] iproute2 : invalid burst/cburst calculation with hrtimers Date: Thu, 5 Feb 2009 10:08:53 +0000 Message-ID: <20090205100853.GB4305@ff.dom.local> References: <200902021926.17768.denys@visp.net.lb> <200902050124.05969.denys@visp.net.lb> <20090205073832.GA4305@ff.dom.local> <200902051101.35327.denys@visp.net.lb> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , netdev@vger.kernel.org To: Denys Fedoryschenko Return-path: Received: from nf-out-0910.google.com ([64.233.182.191]:39745 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755085AbZBEKJA (ORCPT ); Thu, 5 Feb 2009 05:09:00 -0500 Received: by nf-out-0910.google.com with SMTP id d3so19439nfc.21 for ; Thu, 05 Feb 2009 02:08:58 -0800 (PST) Content-Disposition: inline In-Reply-To: <200902051101.35327.denys@visp.net.lb> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Feb 05, 2009 at 11:01:35AM +0200, Denys Fedoryschenko wrote: > Well, i don't know well what's wrong, but: > > I have enough powerful router, 2x Quad Core 2 - 2.8 Ghz > 4 x e1000e > > And if i just try to shape interface for 200 Mbps with default iproute2 from > git (and latest stable release same situation), i am getting too low > burst/cburst. Sometimes it is even miscalculated (it can become 1500 byte, > sometimes, while 1600 is minimum) , because yes, Stephen right, it needs > float. > BUT. > Even i set manually twice more burst/cburst, it is just not enough for 200 > Mbps. I am checking on Cisco, rate is reaching max 180-185Mbps, and even on > this rate buffering in qdiscs and as result jittering hard. > So this 100 bytes, which probably missing, really doesn't matter. > > With 1000 HZ i have > class htb 1:10 parent 1:2 rate 220000Kbit ceil 220000Kbit burst 29067b cburst > 29067b > Sent 14027734219153 bytes 590886842 pkt (dropped 0, overlimits 0 requeues 0) > rate 122452Kbit 17131pps backlog 0b 0p requeues 0 > lended: 171333348 borrowed: 0 giants: 0 > tokens: 980 ctokens: 980 > > And it works quite well and precise. I lost your point... I think it's just like in your (and Martin's) description to your patch. Plus you wrote it was tested OK?! BTW, did you try to set the same (29kb) burst/cburst manually? Did you try with half of it (15kb)? > P.S. Maybe a case, when some guy was not able to reach his gigabit with HTB > shaper, i remember there was flowing some discussing, was somehow similar as > my case. I don't remember this, but with current defaults it's really a problem for higher rates. Jarek P.