Subject: Re: Mainline kernel OLTP performance update

From: "Zhang, Yanmin" <[email-masked]>
Date: Sun, 01 Feb 2009 10:52:56 +0800

On Mon, 2009-01-26 at 12:36 -0500, Christoph Lameter wrote:
> On Sat, 24 Jan 2009, Zhang, Yanmin wrote:
> 
> > But when trying to increased it to 4, I got:
> > [root@lkp-st02-x8664 slab]# echo "3">kmalloc-8192/order
> > [root@lkp-st02-x8664 slab]# echo "4">kmalloc-8192/order
> > -bash: echo: write error: Invalid argument
> 
> This is because 4 is more than the maximum allowed order. You can
> reconfigure that by setting
> 
> slub_max_order=5
> 
> or so on boot.
With slub_max_order=5, the default order of kmalloc-8192 becomes
5. I tested it with netperf UDP-U-4k and the result difference from
SLAB/SLQB is less than 1% which is really fluctuation.