Re: New stacker performance results

From: James Morris (jmorris@private)
Date: Wed May 25 2005 - 23:36:49 PDT


On Thu, 26 May 2005, Colin Walters wrote:

> Ok, this is a more reasonable argument.  Does the strict policy really
> require 17M of kernel memory (that's nonpageable?). 

It's a lot, not sure if it's quite 17, ISTR about 12 (on 32-bit).

> Stephen/James, is there a way SELinux memory usage could be reduced for
> relatively simple policies like this?  Besides older machines, once Xen
> is widely deployed it will be valuable to reduce kernel memory usage so
> that more virtual instances can be deployed on the same machine.

Binary policy could help, although the underlying strategy may 
need to be revised.

I'm sure it's possible; the rules look highly compressable (bzip can
compress the binary policy by an order of magnitude), and the typical
active set of rules is usually very small, perhaps 60 or so for a typical
workload, if that.

So, we could look at using a compressed policy database, which would slow 
down AVC misses, which are typically infrequent.  Even if that was a 
problem, we could provide another cache level between the compressed 
security database and the AVC.  Or something.


- James
-- 
James Morris
<jmorris@private>



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