Stubborn Processes

[kclark at CetaceanNetworks.com (Kevin D. Clark)]

[Permit me to answer your questions out of order]


Steven Erat <stevenerat at yahoo.com> writes:

> Conceivably, the app server might be making calls to custom-built,
> external C++ routines though the app server API to do so, and maybe that
> C++ routine could be somehow nicing the priority of the app server pid to
> set it higher than the kernel pid, but that's a real stretch and the
> client says they are not using such C++ routines.

The problem here has nothing to do with what language the application
is implemented in.  And unless the application is doing something
really, really crazy with priority, I'd doubt that priority has
anything to do with this problem.

> My question is how can it be that root cannot kill a process?  

The process is probably hung waiting for something in kernel space,
most likely in a buggy driver.  I've seen this occur with poorly
written drivers for certain hardware, and I've also seen a process
hang waiting on data from a NFS hard mount (without "intr").

Unfortunately, the only way to kill a process in this state is to
reboot (and then fix the real problem).

Regards,

--kevin
-- 
Kevin D. Clark / Cetacean Networks / Portsmouth, N.H. (USA)
cetaceannetworks.com!kclark (GnuPG ID: B280F24E)
alumni.unh.edu!kdc