schedtool

Queries/alters process' scheduling policy and CPU affinity

Schedtool can query or alter a process' scheduling policy in Linux, specifically assigning SCHED_NORMAL, _FIFO, _RR, _BATCH, _ISO or _IDLEPRIO. It can set static priority for _FIFO and _RR. Setting CPU-affinity and (re)nicing is also possible, making schedtool the definitive interface to Linux scheduler. It can be used to avoid skips and glitches in A/V applications, to lock processes onto given CPUs on SMP/NUMA systems, which may be beneficial for networking or benchmarks, or to adjust nice-levels of lesser important jobs to maintain a high amount of interactive responsiveness under high load. It is also handy to manage realtime processes. If you don't know about scheduling policies, you probably don't want to use this program - or learn and read "man sched_setscheduler". Some supported scheduling policies (such as SCHED_ISO, or SCHED_IDLEPRIO) need a patched kernel (eg. Con Kolivas' -ck patchset).