Re: Mainline kernel OLTP performance update

On Mon, 2009-01-26 at 12:36 -0500, Christoph Lameter wrote:

On Sat, 24 Jan 2009, Zhang, Yanmin wrote:

quoted

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.