understanding pmap

[Yong Huang]

> Linux server 2.6.9-42.0.10.ELsmp #1 SMP Fri Feb 16 17:17:21 EST 2007  i686
> i386 GNU/Linux
...
> Red Hat Enterprise Linux AS release 4 (Nahant Update 4)

That version doesn't have /proc/<pid>/smaps.

> How can I detect the memory leak looking at this?

If a process's virtual memory size keeps increasing and never decreases (or sometimes decreases a little), you can call it a memory leak. When you talk to the developer, you can even find out which segment of the virtual memory is increasing.

> How can I know where is the memory?

What do you mean? The second column of your `pmap -d <pid>' is the memory size and the last column is the file this memory segment maps to, or not mapped to any file if it says anon (anonymous). A competent developer may use info in other columns such as the address to debug and find out which heap in his code the shown anon segment corresponds to.

Yong Huang