Diwaker Gupta
2006-Jan-08 23:06 UTC
[Xen-devel] SEDF unable to enforce hard shares under I/O intensive workloads?
Hi, I have the following setup: o VM1 hosts a webserver serving 10KB files o VM2 hosts a webserver serving 100KB files o dom0, VM1, VM2 all run on the same CPU (I'm running with nosmp, noht flags) o SEDF weights are 2, 2, 2 (equal weights to all) with the extra time flag set to 0 for all (so ideally every domain should get ~32% CPU and no more) I now load the web servers on VM1 and VM2 using external httperf clients. In my tests, I can routinely see dom0 averaging 37% and sometimes going as high as 40%. Has anyone seen this behavior where under I/O intensive workloads SEDF fails to enforce hard shares? Any ideas on how/why this might happen will be much appreciated. BTW, it seems in SEDF only 95% of the CPU is available to the domains. So the remaining 5% is reserved for ? Thanks, Diwaker -- Web/Blog/Gallery: http://floatingsun.net _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel