From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28 Date: Tue, 16 Sep 2008 14:28:25 +0200 Message-ID: <1221568105.5020.17.camel@marge.simson.net> References: <48CAE7A0.8000004@linux-foundation.org> <1221306287.5213.111.camel@marge.simson.net> <48CD1D25.9080301@linux-foundation.org> <1221421907.4597.24.camel@marge.simson.net> <1221475440.4784.39.camel@marge.simson.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1221475440.4784.39.camel-YqMYhexLQo1vAv1Ojkdn7Q@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Christoph Lameter Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List On Mon, 2008-09-15 at 12:44 +0200, Mike Galbraith wrote: > On Sun, 2008-09-14 at 21:51 +0200, Mike Galbraith wrote: > > On Sun, 2008-09-14 at 09:18 -0500, Christoph Lameter wrote: > > > Mike Galbraith wrote: > > > > Numbers from my Q6600 Aldi supermarket box (hm, your box is from different shelf) > > > > > > > My box is an 8p with recent quad core processors. 8G, 32bit Linux. > > > > Don't hold your breath, but after putting my network config of a very > > severe diet, I'm starting to see something resembling sensible results. > > Turns off all netfilter options except tables, etc. > > Since 2.6.22.19-cfs-v24.1 and 2.6.23.17-cfs-v24.1 schedulers are > identical, and these are essentially identical with 2.6.24.7, what I > read from numbers below is that cfs in 2.6.23 was somewhat less than > wonderful for either netperf or tbench, Something happened somewhere > other than the scheduler at 23->24 which cost us some performance, and > another something happened at 26->27. I'll likely go looking again.. > and likely regret it again ;-) Bisecting 26->27 yet again turned up a repeatable downturn in netperf throughput. There is no difference at this point with tbench. Bisect says first bad commit is 847106f, a security merge. Post bisection sanity checkouts say... v2.6.26-21-g2069f45 16384 87380 1 1 60.00 98435.13 16384 87380 1 1 60.01 99259.90 16384 87380 1 1 60.01 99325.61 16384 87380 1 1 60.00 99039.84 v2.6.26-343-g847106f 16384 87380 1 1 60.00 94764.59 16384 87380 1 1 60.00 94909.89 16384 87380 1 1 60.00 94858.63 16384 87380 1 1 60.00 94801.12 ...every time. I knew I'd regret doing this. -Mike