[vox-tech] command to monitor memory usage

[Ken Bloom]

On Sat, 2009-08-22 at 06:57 -0400, Hai Yi wrote:
> Hello friends:
> 
> I was asked in an interview about the command to monitor the memory
> usage, and my answer was "top", however, the interviewer intended for
> the memory usage for individual process, and shamefully I couldn't
> come out with an answer, anyone can elaborate on it?

Top is good if you get the filtering and sorting options right so that
the process you're interested in stays on the list (and doesn't get
crowded out of the list by more resource-hungry programs).

There are various GUI tools (gtop) comes to mind that act like top.

ps can tell you the current memory usage of a given program (when used
in conjunction with grep), and as Pete mentioned, the watch command can
get you that information updated continuously.

There are various memory leak checkers that use LD_PRELOAD to load a
library that may be able to get you more information about specific
kinds of memory usage. Valgrind comes to mind.

There's also kernel tracepoints (http://lwn.net/Articles/346470/) and
resource counters (http://lwn.net/Articles/346303/) that may give you
other useful information about your application's memory usage. I think
these are still on the bleeding edge though.

--Ken