Re: Swapping in 2.6.10 and 2.6.11.11 on a desktop system

Alexander Gretencord
2005-06-15T13:44:32Z

On Tuesday 14 June 2005 18:42, Con Kolivas wrote:
> Try the mapped watermark patch from -ck on 2.6.11*

Unfortunately this patch does not help either. The patch buys me time but then
I get swapping at the 300MB mark. 2.6.8.1 with swappiness=0 swaps later than
this...

These are 'free -m' statistics a minute after reaching the 300MB mark:

total used free shared buffers cached
Mem: 503 498 5 0 36 376
-/+ buffers/cache: 85 418
Swap: 494 227 266

Why does the kernel think that I need 400MB of disk cache when I start some
memory hungry apps? Can't we have a hard limit on disk cache, like: "Don't
use more than 100MB of disk cache".

The problem seems to be that instead of using a big disk cache when theres
plenty of ram and reducing disk cache when applications need the ram, the
disk cache shrinks until a magic watermark and then grows and grows until
theres no ram left for the applications. At least thats the behaviour I am
seeing.

Alex

P.S.: Please cc me as I'm not on the list.