RE: la la la la ... swappiness

["Aucoin" <Aucoin@Houston.RR.com>]

Reformatted as plain text.

________________________________________
From: Aucoin [mailto:Aucoin@Houston.RR.com] 
Sent: Sunday, December 03, 2006 12:17 AM
To: 'akpm@osdl.org'; 'torvalds@osdl.org'; 'linux-kernel@vger.kernel.org';
'clameter@sgi.com'
Subject: la la la la ... swappiness

I set swappiness to zero and it doesn't do what I want!

I have a system that runs as a Linux based data server 24x7 and occasionally
I need to apply an update or patch. It's a BIIIG patch to the tune of
several hundred megabytes, let's say 600MB for a good round number. The
server software itself runs on very tight memory boundaries, I've
preallocated a large chunk of memory that is shared amongst several
processes as a form of application cache, there is barely 15% spare memory
floating around.

The update is delivered to the server as a tar file. In order to minimize
down time I untar this update and verify the contents landed correctly
before switching over to the updated software.

The problem is when I attempt to untar the payload disk I/O starts caching,
the inactive page count reels wildly out of control, the system starts
swapping, OOM fires and there goes my 4 9's uptime. My system just suffered
a catastrophic failure because I can't control pagecache due to disk I/O.
I need a pagecache throttle, what do you suggest?




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/