[Dovecot] unkillable imap process(es) with high CPU-usage

[Edgar Fuß]

> If you can't kill a process with -9, the bug is in the kernel and
> there's nothing Dovecot can do about it. User spaces processes can't
> create unkillable processes unless something's broken.
It just means the process is doing an uninterruptable sleep (in BSD notation, a tsleep() without PCATCH set). This may be an I/O operation, resource shortage etc. and needn't be a kernel bug.