Re: [PATCH] ppc44x: support for 256K PAGE_SIZE

On Oct 19, 2007, at 10:37 AM, Yuri Tikhonov wrote:

On Friday 19 October 2007 03:21, Paul Mackerras wrote:

quoted

Have you measured the performance using a 64kB page size?  If so, how
does it compare with the 256kB page size?

 I measured the performance of the sequential full-stripe write  
operations to
a RAID-5 array (P values below are in MB per second) using the h/w  
accelerated
RAID-5 driver.

 Here are the comparative results for the different PAGE_SIZE values:

PAGE_SIZE = 4K:
 P = 66 MBps;

PAGE_SIZE = 16K:
 P = 145 MBps;

PAGE_SIZE = 64K:
 P = 196 MBps;

PAGE_SIZE = 256K:
 P = 217 MBps.

Is this all in kernel space? or is there a user space aspect to the  
benchmark?

quoted

The 64kB page size has the attraction that no binutils changes are
required.

 That's true, but the additional performance is an attractive thing  
too.

- k