Hi, > > > > To support the limit, surplus CPU is waisted. I don't think > > > > it is a good design. In other words, if every class is satisfied > > > > in terms of its CPU guarantee and some classes can consume more, > > > > surplus CPU should be given to the classes. Therefore, I'm not > > > > interested in supporting the limit currently. > > > > > > Can't you define this limit as "soft" limit? That would address your > > > concerns? > > > > I think Vatsa is differentiating between "hard limit"(class will not get > any resource and the surplus resources will be wasted) and "soft > limit" (class can get resource over its soft limit if there is surplus). > > IMO, advantage of using "soft limit" is that it can be used as a > relative priority when surplus resources are to be allocated to classes. > > For example, consider 3 classes, which are CPU hogs, with soft limits > Class A 20% > Class B 25% > Class C 30% > and when all of them reached their soft limit(total usage 75%), the > remaining 25% can be divided between them proportional to their soft > limit. i.e > Class A would get => 25 * 20/(20+25+30) ==> 6.66% > Class B would get => 25 * 25/(20+25+30) ==> 8.33% > Class C would get => 25 * 30/(20+25+30) ==> 10%
Ah, that make sense. It is an e-series CPU controller's spec, isn't it? > Ideally i would like to see both guarantee and limit supported, as the > main objective of CKRM is empowering the sysadmin with knobs to control > how the system resources are utilized. > > If limit is not a good option (in the current design), then we should > have a "priority", that would decide which class would get preference if > there are surplus resources. > > Priority can be strict (class with priority 2 will get surplus resource > only if the class with priority 1 doesn't need it) or relative (class > with priority 10 will get 10 times of the available surplus resource > than a class with priority 1) Thank you for your suggestions. I stated to discuss with kurosawa-san how we can support limit in the current design. Thanks, MAEDA Naoaki ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ ckrm-tech mailing list https://lists.sourceforge.net/lists/listinfo/ckrm-tech
