"Steinar H. Gunderson" <sgunder...@bigfoot.com> writes: > > So, benchmark: > > - Default: 13266 kN/sec > - Change from ondemand to performance on all cores: 14600 kN/sec > - taskset -c 0-19 (locking affinity to only one set of hyperthreads): > 17512 kN/sec
iirc the main reasons for unbound threads migrating away are: - something else gets scheduled on these logical CPUs, so the scheduler tries to balance to run queue lengths You could check that with perf timechart or perf sched record/map or kernelshark. - there is some IO or communication which causes wakeup affinity. You could try disabling WAKEUP_PREEMPTION or NEXT_BUDDY in /sys/kernel/debug/sched_features -Andi -- a...@linux.intel.com -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
