Subject: Re: RAIDframe queuing policies other than FIFO?
To: Blair Sadewitz <email@example.com>
From: Greg Oster <firstname.lastname@example.org>
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....