On Fri, 2006-04-28 at 12:13 +0400, Kirill Korotaev wrote: > >>>I'm also pretty sure, that CPU controller based on timeslice tricks > >>>behaves poorly on burstable load patterns as well and with interactive > >>>tasks. So before commiting I propose to perform a good testing on > >>>different load patterns. > >> > >>Yes, it can only react very slowly. > > > > > > Actually, this might not be that much of a problem. I know I can > > traverse queue heads periodically very cheaply. Traversing both active > > and expired arrays to requeue starving tasks once every 100ms costs max > > 4usecs (3GHz P4) for a typical distribution. > > with fair scheduling with can be a big problem, as tasks working less > then a tick are hard to account :/
Yeah, tasks dodging the timer interrupt can steal considerable time. I instrumented this once, and caught tasks stealing in excess of 30% of the timeslice of their more lethargic brothers. Generally, they get caught often enough that statistics ~evens the playing field. -Mike ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ ckrm-tech mailing list https://lists.sourceforge.net/lists/listinfo/ckrm-tech