On Wed, 12 Jul 2006 11:30:28 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote:
> > Here are my results: (sequential read, DirectIO)
> > blocksize avg(us) wc(us) total
> > 512 9000 28988 132sec
> > 2048 11057 30976 41sec
> > 16384 25697 61010 12sec
> In general, I would expect that the transfer sizes at the USB level are
> not directly connected with the block sizes you use at the application
> level.
They are, when using open("/foo", O_DIRECT), as long as the underlying
stack supports DirectIO. This mechanism is the official replacement
for /dev/raw now.
> > These numbers tell me that there's a huge overhead (at least 8ms) when
> > starting a transaction. Is this normal?
This seems a bit too much, indeed. But since it's ARM, anything
can happen. It's possible that doing the same thing on a Geode of
similar speed would yield different results.
-- Pete
-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
