kill -9 doesnot work

[tomhorsley at adelphia.net]

> kill -9 doesnot work

Lots of things can get processes into an unkillable state. The most common one
is if the process is in the middle of core dumping - linux won't let you kill it
till it has finished writing the core file (which might take decades if it happens
to be writing the core file over a slow network link).

If the process is being debugged it can also get into a state where it won't
go away with a kill -9, though usually a kill -CONT will get it running enough
to notice the kill -9.

Then there are just plain old bugs, like the process being in a system call with
some mutex locked forever.