From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH 3/3] pkt_sched: restore multiqueue prio scheduler Date: Sun, 24 Aug 2008 21:19:05 +0200 Message-ID: <20080824191905.GA3372@ami.dom.local> References: <1219415417.4672.79.camel@localhost> <20080822221913.GA2981@ami.dom.local> <20080822.173348.232018958.davem@davemloft.net> <20080823084715.GA2515@ami.dom.local> <5f2db9d90808230931n453a3b75q84153dd8c18bcfc2@mail.gmail.com> <1219510193.4732.26.camel@localhost> <5f2db9d90808231209i134a7afbu233269c8ea592422@mail.gmail.com> <20080824075331.GA2721@ami.dom.local> <1219585163.4698.43.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexander Duyck , David Miller , jeffrey.t.kirsher@intel.com, jeff@garzik.org, netdev@vger.kernel.org, alexander.h.duyck@intel.com To: jamal Return-path: Received: from nf-out-0910.google.com ([64.233.182.184]:33821 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751678AbYHXTNT (ORCPT ); Sun, 24 Aug 2008 15:13:19 -0400 Received: by nf-out-0910.google.com with SMTP id d3so589087nfc.21 for ; Sun, 24 Aug 2008 12:13:18 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1219585163.4698.43.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Aug 24, 2008 at 09:39:23AM -0400, jamal wrote: ... > With current controls being per qdisc instead of per netdevice, > the hol fear is unfounded. > You send and when hw cant keep up, you block just the one hwqueue. > While hwqueue is blocked, you can accumulate packets in the prio qdisc > (hence my statement it may not be necessary to accumulate packets in > driver). Jamal, maybe I miss something, but this could be like this only with default pfifo_fast qdiscs, which really are per dev hwqueue. Other qdiscs, including prio, are per device, so with prio, if a band with the highest priority is blocked it would be requeued blocking other bands (hwqueues in Alexander's case). Cheers, Jarek P.