Hello, /proc/sys/kernel/sched_domain/ seems to be somewhat broken when kernel is configured without CONFIG_CPUMASK_OFFSTACK and booting with isolcpus= option.
Example with 8x CPU. With CONFIG_CPUMASK_OFFSTACK=y and "isolcpus=2": # uname -r 5.0.0-0.rc3.git0.1.fc30.x86_64 # ls /proc/sys/kernel/sched_domain/* /proc/sys/kernel/sched_domain/cpu0: domain0 /proc/sys/kernel/sched_domain/cpu1: domain0 /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: domain0 /proc/sys/kernel/sched_domain/cpu4: domain0 /proc/sys/kernel/sched_domain/cpu5: domain0 /proc/sys/kernel/sched_domain/cpu6: domain0 /proc/sys/kernel/sched_domain/cpu7: domain0 Another kernel without CONFIG_CPUMASK_OFFSTACK and "isolcpus=2", so directories missing for CPUs 2-7: # ls /proc/sys/kernel/sched_domain/ cpu0 cpu1 # ls /proc/sys/kernel/sched_domain/* /proc/sys/kernel/sched_domain/cpu0: domain0 /proc/sys/kernel/sched_domain/cpu1: domain0 -Tommi