How to change kernel's system/user mem ratio?

marvin · 03-07-2003, 05:26 AM

I'm using 2.4.19 ( 'cause I'd heard there was an Ext3 bug in 2.4.20 ), and am using me machine as a desktop, only.

Therefore I want all resources devoted to my apps.

Yet, .. the kernel's using 400+MB for cache, and swapping-out my browser/wp/tuxcards/mozilla/etc. ALL the time, and this is VFA ( 'very' and 'annoying' are included in that acronese... )

I'd read, perhaps a year or two ( 3? ) ago, that database users needed to change the user vs. system memory usage ratio of linux to get it to /permit/ the database to use the resources for their intended purpose, and assumed that I'd be able to find that info ( patch? ) when I needed it, but...

go figure.. ( google, howtos, here, ... )

So.

Is there a /proc setting, a change-in-kernel-source-makefile ( or variable ), or ANYTHING that'll permit me to MAKE my machine be used for me, rather than for caching/swapping/thrashing??

swap 700MB used
11MB buffers
450MB cache ( out of 512MB? )

Having to wait for a half-minute, just because I added a bookmark to konq is /murder/.

this-all on
Ath 700 /
512MB SDRAM /
Raid 5 array, 3 drives, for my stuff /
( 2 gxp75's, so raid-5's /really/ necessary .. grumble )
Matrox G400 /
Slackware 8.1

acid_kewpie · 03-07-2003, 06:27 AM

you're presumably thinking of PAM, which you can use to limit users allowed memory uasage, cpu time etc...

http://www.kernel.org/pub/linux/libs...-html/pam.html
http://www.linuxsecurity.com/tips/tip-13.html

marvin · 03-07-2003, 07:11 AM

Kernel reserves most memory for system-processes, and for server/multi-user systems that makes most sense, but for desktop it sucks ****.

Kernel won't permit more than ( apparently ) 25% of RAM to be used by/for userspace processes, so MY APPS get SWAPPED while 75% of RAM is used for .. caching the fs?

*PAM* is a means of reducing user access to resources ( user-management ), but I'm talking about getting the kernel to release resources /for their intended purpose/, unlocking the RAM to the apps it's there to facilitate!

The kernel's built-in choice/ratio is DoS's ME, using my own system.

Win98 didn't do that ...
( but .. it was /really/ lame in other ways )
...

The reason I remembered the patch I'd read-about ( that changed the ratio of system / user memory, within the kernel ) is /because/ this's been an issue
( both for DB users, as noted in me original post, and for desktop single-user machines )