On Wed, Jun 11, 2008 at 05:14:37PM +0200, Oleg Galimov wrote: | Hello all, | | I use cyclictest as a benchmark for my diploma thesis. I have a strange | behavior however, which I can't explain: | | I have a dual-core cpu. When I run cyclictest on both cores and then | start a time hog (like cp /dev/zero /dev/null), then the average latency on | the core where it runs goes down significantly (on my machine it is like | 30us before and 10us after, when using rt-patch). It returns to the | original values, when I kill the cp process. Are you using cpufreq or a similar tool? Cyclictest is not CPU nor I/O intensive and depending on your settings for cpufreq, it may influence the results. Another good test is, along with disabling cpufreq, booting with idle=poll. Luis | I have a similar behavior but less clearly visible with interbench. | | The results appeared so far on 2.6.22, 2.6.22+rt, 2.6.25 and 2.6.25+rt. | | I hope someone can help me explaining this. | | Thank you, | | Oleg Galimov | -- | To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in | the body of a message to majordomo@xxxxxxxxxxxxxxx | More majordomo info at http://vger.kernel.org/majordomo-info.html ---end quoted text--- -- [ Luis Claudio R. Goncalves Bass - Gospel - RT ] [ Fingerprint: 4FDD B8C4 3C59 34BD 8BE9 2696 7203 D980 A448 C8F8 ] -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
