Hi Frank!
`Alien' means that this task is special handled by the Fiasco kernel. In contrast to normal behaviour, L4 syscalls executed in the context of an alien task generate exceptions just before and after the L4 syscall. These exceptions allow the L4Linux server to set the internal Linux state of that task to "disk wait" to prevent that task from the Linux scheduling.
Ok, thank you for the explanation. Where could I read more about that?
The above sample always blocks for exactly the IPC wait time. Then it runs again (accepting input, eg. from keyboard) and blocks again. It can be terminated by pressing CTRL-C as the input seems to be queued until the IPC wait timeout expired.
I cannot check this as I'm currently work with a different branch, but I would expect the exact behaviour as you describe. Or are _all_ Linux applications frozen while this task waits for an incoming IPC?
Yes, that is the problem. As I already described, neither switching to another Linux Console (ALT-F2, ...) nor SSH work when the process blocks - so I guess that all other processes (besides of the test and SSHD) are frozen, too. The freezing of the *single* process is a expected - sure.
Regards Oskar.