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Re: [LUG] Checking on jobs

 

Neil Williams wrote:
> 
> The problem with a GUI monitor is that if the
> process you want to kill is actually taking all the CPU time and/or
> memory, then loading a GUI to kill the process isn't exactly helping
> the CPU! One reason to always keep a terminal window open, I guess.

I usually use "ctrl-alt-f1" to get to a terminal when things are pear
shaped on a desktop.

Since the advent of hyperthreading, a lot of PCs will not get busy with
a single program, if that program only has one thread (and you have an
SMP kernel (old versions of Debian were very good at not installing SMP
kernels by default!)).

Along with memory, another common issue can be a rapidly updating set of
tasks can slow down access to the task list, at least on some kernels.
This can make tools like "top" and "ps" very slow to complete, even
though there is no single process eating CPU, or memory.

A terminology niggle with some messages in the thread, but "ps" and
"top" show "tasks" on Linux. In the old day a task was a process, but
these days a process can have multiple threads of execution, and Linux
exposes these in the list of tasks. Hence the weird looking threads
related to file system handling, or processes like BIND "named" having
more entries than you might expect.

I don't care too much about the terminology, and often say process when
I mean task. But it is important when learning/teaching to
understand/explain what other things are appearing in the list, as you
don't want to zap the wrong thing.

Having used the tradition Unix "top", I'm a big fan of Mr Warner's "top"
shipped in most GNU/Linux distro's, but I'm still learning how to use it
after using it for ages.

I wouldn't like to try and define "job" in this context, but I think it
is generally used as a synonym for "process".

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