From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752204Ab2GTSet (ORCPT ); Fri, 20 Jul 2012 14:34:49 -0400 Received: from merlin.infradead.org ([205.233.59.134]:36882 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751619Ab2GTSes convert rfc822-to-8bit (ORCPT ); Fri, 20 Jul 2012 14:34:48 -0400 Message-ID: <1342805139.2583.46.camel@twins> Subject: Re: [ 11/37] sched/nohz: Rewrite and fix load-avg computation -- again From: Peter Zijlstra To: Jonathan Nieder Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ingo Molnar , Doug Smythies Date: Fri, 20 Jul 2012 19:25:39 +0200 In-Reply-To: <20120720171313.GC2885@burratino> References: <20120717232455.GA5994@kroah.com> <20120717232431.399005532@linuxfoundation.org> <20120717232432.250519502@linuxfoundation.org> <20120718001607.GJ25325@burratino> <1342803898.2583.32.camel@twins> <20120720171313.GC2885@burratino> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-07-20 at 12:13 -0500, Jonathan Nieder wrote: > Peter Zijlstra wrote: > > On Tue, 2012-07-17 at 19:16 -0500, Jonathan Nieder wrote: > > >> I'm thrilled to see this regression fix for stable@, but are we really > >> really sure that it won't cause new regressions? > > > > Doug Smythies ran a ~68 hour test on it, running various synthetic loads > > of various frequencies against it and comparing the reported load > > averages against the expected values and found it to be 'good'. > > > > This doesn't guarantee we won't find more 'interesting' problems in > > there, but it does give me fair confidence in it. > > Yeah, that sounds good. Very nice to hear. > > Is the code to generate the synthetic loads and expected results > somewhere easy to find (like LTP or tools/testing) to make it easier > to keep this code working well in the future? /me finds Doug isn't actually on the CC, /me fixes. Doug had this web-page with all his testing activities, graphs and code etc.. http://www.smythies.com/~doug/network/load_average/ Seems to still work. Last time I tried his scripts they weren't very user friendly, and afaik he's making the pretty graphs 'manually'. But whatever he's got is there I think. If someone wants to take it and make it pretty and 'usable' for people in a hurry I'm sure Doug wouldn't mind.