From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [RCU PATCH 00/14] Remove qdisc lock around ingress Qdisc Date: Fri, 14 Mar 2014 00:28:08 -0700 Message-ID: <5322AF88.60702@gmail.com> References: <20140310170008.3011.73599.stgit@nitbit.x32> <53200588.5060805@mojatatu.com> <53208F11.8010304@gmail.com> <53216FE9.7090604@mojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: xiyou.wangcong@gmail.com, netdev@vger.kernel.org, davem@davemloft.net To: Jamal Hadi Salim Return-path: Received: from mail-ob0-f173.google.com ([209.85.214.173]:41809 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755133AbaCNH2Z (ORCPT ); Fri, 14 Mar 2014 03:28:25 -0400 Received: by mail-ob0-f173.google.com with SMTP id gq1so2168872obb.4 for ; Fri, 14 Mar 2014 00:28:25 -0700 (PDT) In-Reply-To: <53216FE9.7090604@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 03/13/2014 01:44 AM, Jamal Hadi Salim wrote: > On 03/12/14 12:45, John Fastabend wrote: >> On 03/11/2014 11:58 PM, Jamal Hadi Salim wrote: >>> On 03/10/14 13:03, John Fastabend wrote: >> >> Sure I can provide this data as part of the patch description. My >> expectation is now that the qdisc lock is not needed there should >> be less impact to throughput/latency due to filter updates. > > Thats what i would think as well (which would be great). > >> >> Yes upto one RCU grace period. Although I don't think this is an >> issue because we get consistency eventually and even with the qdisc >> lock there is no way to know if a set of skbs hit the filter list >> before or after the update. >> > > Probably not a big issue - but needs to be document clearly since the > expectations have changed. > >> I'll get a v2 out tomorrow morning after making Eric's changes and >> fixing the last compiler warning. >> > > There is one more thing. Actions can be shared. I am wondering how this > change is going to affect it - can you try this attached script? Sorry, > I could have sent a much simpler script - but this is one sitting on > my laptop (i have annotated it - notice the 2 policer instances > are shared). > Would be useful to do pings across two devices at the same time while > concurently doing dumps and see if anything goes crazy (like an oops). Ran the attached script and modified it to match UDP packets so I could use it with pktgen to hammer it a bit more. And changed it to add/delete filters with traffic while doing a watch on the filter and qdisc stats. No oops, splats or anything else crazy. I need to get some sleep now though so the performance numbers will have to wait for tomorrow. Thanks! John -- John Fastabend Intel Corporation