[question] memory usage

[Nick Warne <nick@linicks.net>]

Hi all,

Can anybody explain this to me please.

I have 1.5GB RAM - dmesg (boot -> append="mem=1536M"):

639MB HIGHMEM available.
896MB LOWMEM available.

I have 2GB swap:

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1               1         244     1959898+  82  Linux swap

I have no issues on this - works GREAT.  Normally, after a reboot, and over 
night after logrotate/updatedb etc. run, I end up with about 200MB free RAM 
that is used/reclaimed.  very rarely do I hit disk swap at all (building KDE 
usually grabs about 100Kb, but that is infrequent).

Last week I bought my first DVD player (yes, I know, I am late to the party!).  
When I watch a DVD (Xine), memory usage hardly goes up (no swap ever used).  
But after finishing, I then see memory usage is way down:


nick@linuxamd:nick$ uptime; free
 21:11:26 up 1 day,  4:57,  1 user,  load average: 0.06, 0.10, 0.26
             total       used       free     shared    buffers     cached
Mem:       1556216     411144    1145072          0      28408     236704
-/+ buffers/cache:     146032    1410184
Swap:      1959888          0    1959888


Why is this?

Thanks,

Nick

-- 
"Person who say it cannot be done should not interrupt person doing it."
-Chinese Proverb