From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH 1/1] net_sched: drr: warn when qdisc is not work conserving Date: Thu, 12 Jun 2014 18:03:08 +0200 Message-ID: References: <1402511718-24203-1-git-send-email-fw@strlen.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To: Florian Westphal , netdev@vger.kernel.org Return-path: Received: from stinky.trash.net ([213.144.137.162]:56896 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755968AbaFLQDS (ORCPT ); Thu, 12 Jun 2014 12:03:18 -0400 In-Reply-To: <1402511718-24203-1-git-send-email-fw@strlen.de> Sender: netdev-owner@vger.kernel.org List-ID: On 11. Juni 2014 20:35:18 MESZ, Florian Westphal wrote: >The DRR scheduler requires that items on the active list are work >conserving, i.e. do not hold on to skbs for throttling purposes, etc. >Attaching e.g. tbf renders DRR useless because all other classes on the >active list are delayed as well. > >So, warn users that this configuration won't work as expected; we >already do this in couple of other qdiscs, see e.g. Why don't prevent this during configuration time in the first place? It doesn't work, a warning might trigger long after creating the broken configuration and will more likely go unnoticed.