On Linux, system load is defined as the exponentially decaying average of num runnable processes + num uninterruptable processes. I am wondering if it will correctly account for CFS cgroup quota used to limit the number of cpu shares a group of processes may use in a given interval. In other word: If a proces…
Tag: cfs
Completely Fair Scheduler (CFS): vruntime of long running processes
If vruntime is counted since creation of a process how come such a process even gets a processor if it is competing with a newly created processor-bound process which is younger let say by days? As I’ve read the rule is simple: pick the leftmost leaf which is a process with the lowest runtime. Thanks! A…
Linux SCHED_OTHER, SCHED_FIFO and SCHED_RR – differences
Can someone explain the differences between SCHED_OTHER, SCHED_FIFO and SCHED_RR? Thanks Answer SCHED_FIFO and SCHED_RR are so called “real-time” policies. They implement the fixed-priority real-time scheduling specified by the POSIX standard. Tasks with these policies preempt every other task, wh…