From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH] net_sched: fix dequeuer fairness Date: Sun, 26 Jun 2011 12:13:46 -0400 Message-ID: <1309104826.5134.46.camel@mojatatu> References: <1309097254.5134.24.camel@mojatatu> <1309100994.2532.35.camel@edumazet-laptop> <1309102334.5134.31.camel@mojatatu> <1309103630.2532.42.camel@edumazet-laptop> Reply-To: jhs@mojatatu.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Miller , Herbert Xu , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:35767 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751694Ab1FZQNt (ORCPT ); Sun, 26 Jun 2011 12:13:49 -0400 Received: by iwn6 with SMTP id 6so3527939iwn.19 for ; Sun, 26 Jun 2011 09:13:49 -0700 (PDT) In-Reply-To: <1309103630.2532.42.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 2011-06-26 at 17:53 +0200, Eric Dumazet wrote: > > This is because of commit 24f8b2385e03a4f. > > Prior to this, we could exit very fast from this function, even after > receiving a single packet. > > jiffies break is kind of lazy, IMHO ;) And subjective to the value of Hz. In the case of net_rx_action it seems that we need "something" other than packet budget to get us out of there in extreme case when we loop and none of the netdevs have anything to offer. In the other extreme it would be very unfair to yield because of jiffies when budget is not exhausted and devices have something to offer. One approach could be to deduct their napi weight when they return a 0 for work done. cheers, jamal