[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] xen 4.5.0 rtds scheduler perform poorly with 2vms
2015-11-29 7:46 GMT-05:00 Yu-An(Victor) Chen <chen116@xxxxxxx>:
âHi, â Â
âNice! :-)â Â
â(I like this line, BTW. :-D)â Â
âyes, this is the information I need and we can solve the mystery now... Let's look at this task: (period, exe, deadline)=(21ms,12.023ms,21ms) -> miss all deadline Its utilization is 12.023 / 21 ~= 0.5614; Your VCPU utilization is only 2ms / 4ms = 0.5 So even when this task is pinned to one VCPU, it will still miss deadline because it has only one thread. :-) If you use one VCPU with 100% utilization, you should not see the deadline miss from this task. Or at least, it won't have all jobs missing deadline. âSo basically, it is because your configuration is incorrect. That's also why you need to read some literatures in real-time scheduling theory. ;-) â â Â
âThat's carry-over workload. It is common in the overloaded situation under real-time scheduling. â Â
Yeah, you need to read and learn the real-time scheduling theory, especially you are doing research in RT field. :-DÂ Â
âHope it helps. :-) Best, Mengâ Â
----------- Meng Xu PhD Student in Computer and Information Science University of Pennsylvania http://www.cis.upenn.edu/~mengxu/ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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