Re: Memory, where's it going?

From: Shaun
Date: Wed Dec 28 2005 - 04:07:37 EST


I understand the concept and why things are cached, i've just never seen it cache this much before.. usually on a machine with bearly anything running on it (like this one) it uses bearly any memory at all. My concern is that with bearly anything running on it i already have dug into swap.

Thanks for the responce, i just wanted to make sure their wasnt some type of a memory bug.

~Shaun
----- Original Message ----- From: "DervishD" <lkml@xxxxxxxxxxxx>
To: "Shaun" <mailinglists@xxxxxxxxxxxxxxxx>
Cc: <linux-kernel@xxxxxxxxxxxxxxx>
Sent: Wednesday, December 28, 2005 12:53 AM
Subject: Re: Memory, where's it going?


Hi Shaun :)

* Shaun <mailinglists@xxxxxxxxxxxxxxxx> dixit:
I see that free shows that 7.7GB is cached and i'm not sure why so
much is cached.

Because free memory is a *waste* of memory. Why leaving unused
memory when it can be used for caching? The kernel will (up to some
extent, I suppose) try to use all free memory for caching if no app
needs it.

If you have 8GB of memory, it's a bit difficult to fill it just
with the running apps, so the kernel cleverly uses the rest for
caching things so the system runs faster.

For example, I have 1GB of RAM, and even when I use X (seldom...)
I never eat up more than, let's say, 500MB. So, I have another 500MB
of memory unused: the kernel uses it as cache, and that makes my
system run much faster (I noticed a speed increase when I switch from
512 to 1G).

Raúl Núñez de Arenas Coronado

--
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to...


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