Re: Query about failure of Debian 6 64 bit to swap properly

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Mittwoch, 29. August 2012 schrieb Bob Proulx:
> Then press F6 to change the sort function.  Use the up and down cursor
> keys to select VIRT for sorting by size of virtual memory usage.  What
> programs are the top virtual memory consumers on your system?  (On
> mine it is usually firefox.)  Based upon what those memory hogs are on
> your system we can advise what action might be taken.

No!

Virtual memory size does not say a single thing about real physical memory 
usage.

An application can happily allocate 1 GiB or more of virtual memory 
without every having the Linux kernel allocating physical memory at all 
except for the management of the memory allocation at all.

Virtual memory is just address space. Unless the application writes to it, 
the kernel does nothing, repeat, nothing in physical memory.

So its resident set size. And even that is not accurate, cause it usually 
collects libary memory usage as well.

So when you have 100 processes using libc6 the library is still in memory 
just once. So an approach is account to the process the resident set size 
of the library divided by the amount of processes that use it.

In newer KDE versions the process monitor has a detailed memory statistics 
page that does just that. I never have seen that in a shell command up to 
know.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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