On 08/12, Adrian Reber wrote: > > The main motivation to add set_tid to clone3() is CRIU. > > To restore a process with the same PID/TID CRIU currently uses > /proc/sys/kernel/ns_last_pid. It writes the desired (PID - 1) to > ns_last_pid and then (quickly) does a clone(). This works most of the > time, but it is racy. It is also slow as it requires multiple syscalls. > > Extending clone3() to support set_tid makes it possible restore a > process using CRIU without accessing /proc/sys/kernel/ns_last_pid and > race free (as long as the desired PID/TID is available). > > This clone3() extension places the same restrictions (CAP_SYS_ADMIN) > on clone3() with set_tid as they are currently in place for ns_last_pid. > > Signed-off-by: Adrian Reber <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
