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 11:56:32 +0000 Message-ID: <20090205115631.GC4305@ff.dom.local> References: <200902021926.17768.denys@visp.net.lb> <200902051101.35327.denys@visp.net.lb> <20090205100853.GB4305@ff.dom.local> <200902051309.06958.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 mail-fx0-f20.google.com ([209.85.220.20]:52726 "EHLO mail-fx0-f20.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753148AbZBEL4i (ORCPT ); Thu, 5 Feb 2009 06:56:38 -0500 Received: by fxm13 with SMTP id 13so310936fxm.13 for ; Thu, 05 Feb 2009 03:56:36 -0800 (PST) Content-Disposition: inline In-Reply-To: <200902051309.06958.denys@visp.net.lb> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Feb 05, 2009 at 01:09:06PM +0200, Denys Fedoryschenko wrote: > On Thursday 05 February 2009 12:08:53 Jarek Poplawski wrote: > > > > 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?! > Martin just pointed me, that burst/cburst probably is too small. > > I found, that it is too small because of get_hz(). Actually on highres it will > be always 1600 (default minimal value). And these are very good points. > > BTW, did you try to set the same (29kb) burst/cburst manually? Did > > you try with half of it (15kb)? > I didn't, i guess i must calculate corresponding rates for another classes > equally. But i try to set HZ variable to 2000 for example, i will see: > > class htb 1:10 parent 1:2 rate 220000Kbit ceil 220000Kbit burst 15317b cburst > 15317b > Sent 100864803 bytes 115615 pkt (dropped 0, overlimits 0 requeues 0) > rate 15426Kbit 2106pps backlog 0b 0p requeues 0 > lended: 29467 borrowed: 0 giants: 0 > tokens: 533 ctokens: 533 > > But it is difficult to know, if it works fine or not. I will try to do more > tests for 2000 and 10000 HZ. The issue, that on that point where i had fault, > now is less load, so i have to find another place where i can test > differences. I don't know where else in tc this HZ env. variable is used, so this could change more than you need. I only wondered if setting this manually works, so one try should be enough. Since you tested with double size burst (~3kb?) and it didn't work, then we know even 10000 (10x) get_hz() would be wrong. This 2x case is only for curiosity but I think there is no reason to use more than 1000HZ for setting these defaults in tc. Jarek P.