From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [RFC PATCH 00/12] drop the qdisc lock for pfifo_fast/mq Date: Thu, 07 Jan 2016 15:30:58 -0800 Message-ID: <568EF532.4040307@gmail.com> References: <20151230175000.26257.41532.stgit@john-Precision-Tower-5810> <568D1344.1090602@mojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: john.r.fastabend@intel.com, netdev@vger.kernel.org To: Jamal Hadi Salim , daniel@iogearbox.net, eric.dumazet@gmail.com, aduyck@mirantis.com, brouer@redhat.com, davem@davemloft.net Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:34660 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181AbcAGXbQ (ORCPT ); Thu, 7 Jan 2016 18:31:16 -0500 Received: by mail-pf0-f176.google.com with SMTP id q63so519849pfb.1 for ; Thu, 07 Jan 2016 15:31:16 -0800 (PST) In-Reply-To: <568D1344.1090602@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 16-01-06 05:14 AM, Jamal Hadi Salim wrote: > > Sorry for not being as responsive as i would like to be > (theman calls and i have to go). > This looks like a good (tc workshop) candidate discussion, if still > active by netdev11 time. > > On 15-12-30 12:50 PM, John Fastabend wrote: >> Hi, >> >> This is a first take at removing the qdisc lock on the xmit path >> where qdiscs actually have queues of skbs. The ingress qdisc >> which is already lockless was "easy" at least in the sense that >> we did not need any lock-free data structures to hold skbs. >> > > I did some testing over the holidays for a netdev11 paper submission > and the ingress qdisc side of things looks very impressive (on > an average packet size) on a single (i7 class) cpu. > It can handle about 3x what an egress side pktgen type test (not > very real life) can handle. Analysis shows the lock is killing us. > So if you are looking at low hanging fruit, the egress is > the place to look. So this series drops the qdisc lock which should hopefully per some older data I have bring it on par with the ingress side. But I need to retest this latest patch series. > I have a pktgen change that may be useful for you - I will post > it next time i get cycles. > I am also a willing guinea pig (given upcoming netdev11) to do > some perf testing ;-> > I typically test this by putting vlan's on top of a dev with the qdisc I want to test and running pktgen on the vlans the entry point of the skb is pretty much where I want it in this case. > cheers, > jamal > >