Did you double-check that you were not testing Xenomai with the "vanilla" cyclictest, ie. the one without libpthread_rt dependencies...? See "ldd cyclictest" when in doubt.
Yes, I did. I wanted to know performances of cyclictest without Xenomai to compare. And I thought that even with Xenomai in the kernel, I would have the same result. On 6/6/07, Philippe Gerum <[EMAIL PROTECTED]> wrote:
On Wed, 2007-06-06 at 15:04 +0000, Daniel Schnell wrote: > Try adding -p99 to use realtime. > > > ________________________________ > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Perrine Martignoni > Sent: 6. júní 2007 15:02 > To: xenomai-help > Subject: [Xenomai-help] Cyclictest > > > Hello, > > I launched the same application Cyclictest on a kernel Linux without Xenomai and a kernel Linux with Xenomai and I noticed that the result is different. > > Here is the result with a kernel Linux without xenomai : > > > cyclictest -t 10 -c 1 -i 10500 > > > T: 0 ( 732) P:99 I: 10500 C: 2291 Min: 41 Act: 2281 Avg: 5075 Max: 10224 > > T: 1 ( 733) P:98 I: 11000 C: 2187 Min: 66 Act: 1312 Avg: 5085 Max: 10236 > > T: 2 ( 734) P:97 I: 11500 C: 2092 Min: 91 Act: 842 Avg: 5113 Max: 10311 > > T: 3 ( 735) P:96 I: 12000 C: 2004 Min: 106 Act: 1384 Avg: 5134 Max: 10140 > > T: 4 ( 736) P:95 I: 12500 C: 1924 Min: 116 Act: 9873 Avg: 5152 Max: 10306 > > T: 5 ( 737) P:94 I: 13000 C: 1850 Min: 136 Act: 415 Avg: 5172 Max: 10376 > > T: 6 ( 738) P:93 I: 13500 C: 1782 Min: 136 Act: 3873 Avg: 5180 Max: 10411 > > T: 7 ( 751) P:92 I: 14000 C: 1722 Min: 156 Act: 3559 Avg: 5184 Max: 10190 > > T: 8 ( 752) P:91 I: 14500 C: 1663 Min: 140 Act: 8454 Avg: 5216 Max: 10310 > > T: 9 ( 753) P:90 I: 15000 C: 1608 Min: 184 Act: 2485 Avg: 5214 Max: 10490 > > > > And here is the result with a kernel Linux with xenomai : > > cyclictest -t 10 -c 1 -i 10000 > > > T: 0 ( 893) P:99 I: 10000 C: 1756 Min: 13407 Act: 13536 Avg: 13452 Max: 13693 > > T: 1 ( 894) P:98 I: 10500 C: 1673 Min: 4955 Act: 7595 Avg: 9767 Max: 14727 > > T: 2 ( 895) P:97 I: 11000 C: 1597 Min: 5461 Act: 7628 Avg: 10047 Max: 14793 > > T: 3 ( 908) P:96 I: 11500 C: 1333 Min: 4987 Act: 5641 Avg: 9808 Max: 14779 > > T: 4 ( 909) P:95 I: 12000 C: 1277 Min: 5478 Act: 11665 Avg: 9588 Max: 13864 > > T: 5 ( 910) P:94 I: 12500 C: 1226 Min: 6016 Act: 11191 Avg: 9859 Max: 14135 > > T: 6 ( 911) P:93 I: 13000 C: 1179 Min: 5526 Act: 9711 Avg: 10130 Max: 14901 > > T: 7 ( 912) P:92 I: 13500 C: 1135 Min: 5061 Act: 14740 Avg: 9896 Max: 14852 > > T: 8 ( 913) P:91 I: 14000 C: 1095 Min: 5549 Act: 7766 Avg: 9669 Max: 14198 > > T: 9 ( 914) P:90 I: 14500 C: 1057 Min: 5107 Act: 11820 Avg: 9940 Max: 14984 > > > > We can see that with Xenomai, the results are less good. > Is there an explication to this? Actually, you don't have any information from this test output unless you did put some load on your box. Real-time is about predictability, what Xenomai brings is exactly that. Raw performances have no meaning in a real-time context unless they can be sustained regardless of the runtime conditions. If your box is not some flashy big iron, try putting some load with this command while the test is running, on both boxen: while :; do dd if=/dev/zero of=hog.out count=500 bs=1M; rm -f hog.out && sync; done If you do have a recent, multi-core and multi-Ghz box, try compiling a kernel over all the CPUs when testing. E.g. for a 2 CPU box, try running: while :; do make clean && make -j3; done > > Thanks > > _______________________________________________ > Xenomai-help mailing list > [email protected] > https://mail.gna.org/listinfo/xenomai-help -- Philippe.
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