On Thu, Nov 19, 2020 at 01:13:20PM +0000, Will Deacon wrote: > Sure, but I was talking about what userspace sees, and I don't think it ever > sees CPUs that have been hotplugged off, right? That is, sched_getaffinity() > masks its result with the active_mask. # for i in /sys/devices/system/cpu/cpu*/online; do echo -n $i ":"; cat $i; done /sys/devices/system/cpu/cpu1/online :0 /sys/devices/system/cpu/cpu2/online :1 /sys/devices/system/cpu/cpu3/online :1 /sys/devices/system/cpu/cpu4/online :1 /sys/devices/system/cpu/cpu5/online :1 /sys/devices/system/cpu/cpu6/online :1 /sys/devices/system/cpu/cpu7/online :1 # grep Cpus_allowed /proc/self/status Cpus_allowed: ff Cpus_allowed_list: 0-7 :-)
