On Wed, Feb 12, 2003 at 09:53:15PM +0100, martin f krafft wrote: | i have a process waiting for data on a device that doesn't exist | anymore (USB). now the process is listed as uninterruptibly sleeping. | i want to get rid of it, but kill -9 doesn't do anything, the process | remains. | | what must i do to kill this process? it can't be that i can get | a process to lock into the scheduler so as to not get out anymore...
The process isn't "locked into the scheduler" -- the (CPU) scheduler
always bypasses it because the process doesn't want any CPU right now.
The process' PC (Program Counter) is currently pointing to
instructions that are part of the kernel. It is waiting for some I/O
activity. The processs can't be killed outright because that would
harm the integrity of the running kernel. Once the process is back in
user space it can be killed with SIGKILL. Unfortunately, it isn't
likely the process will ever become unblocked.
I think, but am not 100% positive, that the Hurd doesn't have this
problem. My reasoning is every Hurd process always runs in user space
and requests device I/O from a specialty process via IPC. It is
possible, though, that the process that actually does the device I/O
could become permanently blocked.
-D
--
How great is the love the Father has lavished on us,
that we should be called children of God!
1 John 3:1
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