Comment 27 for bug 1058864

As another data point, I loaded the Ubuntu 8.04-4 x86 LiveCD and rebuilt the executable and ran the test. I then ran the same executable on the Ubuntu 7.10 x86 LiveCD and the Ubuntu 12.04 x64 Install (after installing ia32-libs) and here are the results. I chose those release because those were the ones that straddled the switch to the Completely Fair Scheduler (CFS). In the mutex and benaphore cases, there definitely appears to be a regression in performance between Ubuntu 7.10 and Ubuntu 8.04. In the mutex2 case, Ubuntu 8.04 seems to outperform 7.10.

By and large, Ubuntu 12.04 seems to be inline with Ubuntu 8.04, but the results in the benaphore case appear to have further regressed.

Here are the actual results:

Ubuntu 7.10
mutex
real 0m 0.671s user 0m 0.672s sys 0m 0.000s
real 0m 3.641s user 0m 4.128s sys 0m 2.476s
real 0m 9.673s user 0m10.845s sys 0m16.433s
real 0m18.666s user 0m18.949s sys 0m45.251s
real 0m41.603s user 0m45.671s sys 1m59.703s

benaphore
real 0m 0.433s user 0m 0.432s sys 0m 0.000s
real 0m 4.441s user 0m 2.912s sys 0m 4.476s
real 0m14.732s user 0m10.349s sys 0m31.250s
real 0m31.096s user 0m23.193s sys 1m24.241s
real 0m54.901s user 0m42.991s sys 2m55.435s

mutex2
real 0m 0.397s user 0m 0.396s sys 0m 0.004s
real 0m 1.154s user 0m 1.668s sys 0m 0.552s
real 0m 3.840s user 0m 8.001s sys 0m 7.244s
real 0m 5.401s user 0m11.845s sys 0m 9.621s
real 0m11.053s user 0m24.422s sys 0m19.685s

Ubuntu 8.04
mutex
real 0m 0.581s user 0m 0.580s sys 0m 0.000s
real 0m 4.565s user 0m 5.696s sys 0m 3.400s
real 0m14.395s user 0m14.137s sys 0m33.518s
real 0m29.346s user 0m24.862s sys 1m31.506s
real 0m50.856s user 0m46.871s sys 2m36.462s

benaphore
real 0m 0.331s user 0m 0.328s sys 0m 0.000s
real 0m 5.629s user 0m 3.340s sys 0m 4.684s
real 0m22.760s user 0m17.581s sys 0m55.155s
real 0m32.677s user 0m27.390s sys 1m42.750s
real 1m 7.969s user 1m 0.220s sys 3m31.481s

mutex2
real 0m 0.402s user 0m 0.404s sys 0m 0.000s
real 0m 0.841s user 0m 0.980s sys 0m 0.548s
real 0m 2.578s user 0m 4.140s sys 0m 6.024s
real 0m 4.329s user 0m 6.556s sys 0m10.573s
real 0m 9.003s user 0m13.417s sys 0m22.329s

Ubuntu 12.04
mutex
real 0m 0.515s user 0m 0.512s sys 0m 0.000s
real 0m 4.001s user 0m 4.820s sys 0m 3.148s
real 0m11.198s user 0m11.669s sys 0m25.246s
real 0m19.938s user 0m16.861s sys 1m 1.536s
real 0m48.183s user 0m37.994s sys 2m33.446s

benaphore
real 0m 0.319s user 0m 0.320s sys 0m 0.000s
real 0m 4.868s user 0m 5.760s sys 0m 3.900s
real 0m19.777s user 0m16.613s sys 0m46.351s
real 0m48.226s user 0m34.098s sys 2m37.834s
real 1m38.550s user 1m10.000s sys 5m22.892s

mutex2
real 0m 0.337s user 0m 0.332s sys 0m 0.000s
real 0m 0.875s user 0m 0.988s sys 0m 0.744s
real 0m 2.082s user 0m 3.124s sys 0m 5.148s
real 0m 4.114s user 0m 5.368s sys 0m10.825s
real 0m 8.069s user 0m10.785s sys 0m21.289s