Subject: Re: maximum size of 8KB in copyin\out
To: , <tech-kern@netbsd.org>
From: Toru Nishimura <locore64@alkyltechnology.com>
List: tech-kern
Date: 03/10/2007 09:50:30
> What do you think the reason we are seeing maximum of 8KB on
> copyin\out although we are telling dd to use 128KB block size. we are
> reading from SATA disk (SCSI implementation) or USB disk .

It's because block I/O scheme does.

And I'm anxious that you're pursuing the wrong direction to enhance
I/O performance by adding DMA HW for copyin/out.  You will find the
reason as deeper you learn.

Toru Nishimura/ALKYL Technology