Hi, There seems to be some additional insight. Trying to kill the processes so the testsuite might hopefully continue, this was the result: unkillable (-SIGKILL) processes, which can also not be traced with strace, and neither the selftest suite continued. root 1000955 2931 0 01:05 pts/2 00:00:00 ./pidfd_setns_test root 1000956 1000955 99 01:05 pts/2 14:09:03 [pidfd_setns_tes] <defunct> root 1037946 1005609 0 15:19 pts/3 00:00:00 grep --color=auto pidfd_setns_tes root@defiant:/home/marvin/linux/kernel/net-next# strace -p 1000955 strace: Could not attach to process. If your uid matches the uid of the target process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf: Operation not permitted strace: attach: ptrace(PTRACE_SEIZE, 1000955): Operation not permitted root@defiant:/home/marvin/linux/kernel/net-next# strace -p 1000956 strace: Could not attach to process. If your uid matches the uid of the target process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf: Operation not permitted strace: attach: ptrace(PTRACE_SEIZE, 1000956): Operation not permitted root@defiant:/home/marvin/linux/kernel/net-next# Hope this helps. It would be very interesting to see now what exactly eats 99% of a CPU core, but I am not enough technologically savvy for this task ATM. Best regards, Mirsad Todorovac
