From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Devera Subject: Re: Not understand some in htb_do_events function Date: Tue, 15 Jan 2008 22:58:29 +0100 Message-ID: <478D2C85.2090008@cdi.cz> References: <478C86E6.3050508@bigtelecom.ru> <478C87D9.1010305@trash.net> <478CA02A.1070308@cdi.cz> <478CD741.7040004@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Badalian Vyacheslav , netdev@vger.kernel.org To: Patrick McHardy Return-path: Received: from www1.cdi.cz ([194.213.194.49]:34078 "EHLO www1.cdi.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755964AbYAOV6e (ORCPT ); Tue, 15 Jan 2008 16:58:34 -0500 In-Reply-To: <478CD741.7040004@trash.net> Sender: netdev-owner@vger.kernel.org List-ID: > > So this was meant to protect against endless loops? > >> We want way to smooth big burst of events over more dequeue invocations >> in order to not slow dequeue too much. Constant 500 is max. allowed >> "slowdown" of dequeue. >> Any bright idea how to do it more elegant, Patrick ? > > > Unfortunately not, but I believe simply removing the limit > completely would be better than picking an arbitary value. Grrr my comp crashed while I was writing this mail. Well the second attempt. When we allow unlimited events per dequeue, then there is case where all N classes in qdisc can be in the event queue with the same target time. Then they will all be acted on in the loop within single dequeue, costing us say some milliseconds. Additionaly, it tends to repeat itself then in cycles. Maybe it is acceptable but it seemed to me as rather big latency. Thus I wanted to do only limited work per dequeue call. One possibility is to remove the limit and "see what happend in wild". What do u think about to do limited no of transitions and then schedule tasklet to do the rest (again in limited buckets) ?