Subject: Re: RAIDframe queuing policies other than FIFO?
To: Blair Sadewitz <>
From: Greg Oster <>
List: tech-kern
Date: 08/13/2007 12:05:50
"Blair Sadewitz" writes:
> Has anyone compared the performance of the other RAIDframe queue
> strategies?  I'm especially interested in reasons to choose one based
> upon different workloads.  There is precious little documentation on
> this other than comments in the source and certain academic papers
> which are a bit too wide (or narrow) in scope to be of general
> usefulness to NetBSD users.
> Additionally, would it make sense to choose a bufq strategy in the
> kernel based upon the RAIDframe queueing strategy, or vice versa?  For
> example, using BUFQ_PRIOCSCAN with RAIDframe's sstf, or using disksort
> with cscan?  What about fcfs with sstf?  Inquiring minds want to know!
> ;)

Inquiring minds might also want to know that there is no support
for alternate RAIDframe queuing strategies in the component label 
stuff -- the use of fifo is basically hard-coded for anything 
using 'autoconfig'....  So you'll need to do a 'raidctl -c' and not 
use autoconfig to get the alternate queue type... 

I'd be interested in seeing any benchmarks on this as well....


Greg Oster