Messages in this thread | | | Subject | Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28 | From | Mike Galbraith <> | Date | Tue, 16 Sep 2008 14:28:25 +0200 |
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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
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