New low latency kernel flavour (was "Lucid server flavour RFC")

[Alessio Igor Bogani]

Hi All,

2010/1/20 Tim Gardner <tim.gardner at canonical.com>:
> I'm considering an additional Lucid x86_64 flavour, one tuned for low
> latency, power consumptive platforms. I've received a fair bit of

I think that UbuntuStudio would really appreciate that new flavour, please do!

I built a test "-lowlatency" kernelinto my PPA:
http://kernel.ubuntu.com/~abogani/

Anyone interested into that new kernel flavour is invited to test it
and report result to list!

I have done some "inaccurate" tests measured with cyclictest (rt-tests
package) and with a  common workload (generated with some programs:
Totem, OpenOffice.org, Firefox, dd, ping, top, make -j2) for a couple
of minutes. Not very reliable tests after all but they could help to
understand the right way. Please take a look of the latests test which
have a very good results!

config.generic
T: 0 ( 2146) P:99 I:1000 C:  58975 Min:      6 Act:  211 Avg:  150 Max:     357
T: 1 ( 2147) P:98 I:1500 C:  39317 Min:      6 Act:  206 Avg:  155 Max:     338
T: 2 ( 2148) P:97 I:2000 C:  29488 Min:      6 Act:  200 Avg:  144 Max:     358
T: 3 ( 2149) P:96 I:2500 C:  23591 Min:      6 Act:  394 Avg:  143 Max:     394
T: 4 ( 2150) P:95 I:3000 C:  19659 Min:      7 Act:  204 Avg:  140 Max:     318

config.generic.1000hz
T: 0 ( 2620) P:99 I:1000 C:  59012 Min:      5 Act:   37 Avg:   26 Max:     173
T: 1 ( 2621) P:98 I:1500 C:  39342 Min:      4 Act:  186 Avg:   22 Max:     186
T: 2 ( 2622) P:97 I:2000 C:  29507 Min:      4 Act:  130 Avg:   22 Max:     148
T: 3 ( 2623) P:96 I:2500 C:  23605 Min:      4 Act:    6 Avg:   22 Max:     190
T: 4 ( 2624) P:95 I:3000 C:  19671 Min:      5 Act:    7 Avg:   20 Max:     156

config.generic.1000hz.nohz_off_via_cmdline
T: 0 ( 2077) P:99 I:1000 C:  58989 Min:      5 Act:  197 Avg:  133 Max:     438
T: 1 ( 2078) P:98 I:1500 C:  39327 Min:      5 Act:  199 Avg:  132 Max:     357
T: 2 ( 2079) P:97 I:2000 C:  29495 Min:      5 Act:  194 Avg:  133 Max:     502
T: 3 ( 2080) P:96 I:2500 C:  23597 Min:      6 Act:  201 Avg:  132 Max:     298
T: 4 ( 2081) P:95 I:3000 C:  19664 Min:      5 Act:  194 Avg:  132 Max:     274

config.generic.nohz_off
T: 0 ( 2177) P:99 I:1000 C:  58975 Min:      5 Act:   81 Avg:   28 Max:     214
T: 1 ( 2178) P:98 I:1500 C:  39317 Min:      5 Act:   25 Avg:   24 Max:     222
T: 2 ( 2179) P:97 I:2000 C:  29488 Min:      6 Act:   20 Avg:   22 Max:     129
T: 3 ( 2180) P:96 I:2500 C:  23591 Min:      6 Act:  260 Avg:   21 Max:     260
T: 4 ( 2181) P:95 I:3000 C:  19659 Min:      5 Act:   22 Avg:   19 Max:     110

config.generic.nohz_off.1000hz
T: 0 ( 2268) P:99 I:1000 C:  59016 Min:      4 Act:    7 Avg:   28 Max:     171
T: 1 ( 2269) P:98 I:1500 C:  39345 Min:      4 Act:  171 Avg:   19 Max:     171
T: 2 ( 2270) P:97 I:2000 C:  29509 Min:      4 Act:  124 Avg:   22 Max:     346
T: 3 ( 2271) P:96 I:2500 C:  23607 Min:      4 Act:    7 Avg:   20 Max:     197
T: 4 ( 2272) P:95 I:3000 C:  19673 Min:      4 Act:   10 Avg:   23 Max:     104

config.generic.nohz_off.1000hz.slab.preempt_rcu.preempt
T: 0 ( 2077) P:99 I:1000 C:  58990 Min:      5 Act:    8 Avg:   28 Max:     164
T: 1 ( 2078) P:98 I:1500 C:  39327 Min:      5 Act:    8 Avg:   25 Max:     153
T: 2 ( 2079) P:97 I:2000 C:  29496 Min:      5 Act:   10 Avg:   19 Max:     120
T: 3 ( 2080) P:96 I:2500 C:  23597 Min:      5 Act:   12 Avg:   24 Max:     159
T: 4 ( 2081) P:95 I:3000 C:  19664 Min:      5 Act:   11 Avg:   22 Max:     143

Ciao,
Alessio