I see ? in the S column of htop output. But the manpage only has the following states. What does ? mean? Thanks.
STATE (S)
The state of the process:
S for sleeping (idle)
R for running
D for disk sleep (uninterruptible)
Z for zombie (waiting for parent to read its exit status)
T for traced or suspended (e.g by SIGTSTP)
W for paging
