CAM disk I/O starvation

[Gary Jennejohn]

On Thu, 5 Apr 2012 05:22:46 +0200
Alexander Leidinger <Alexander at Leidinger.net> wrote:

> On Tue, 3 Apr 2012 14:27:43 -0700 Jerry Toung <jrytoung at gmail.com>
> wrote:
> 
> > On 4/3/12, Gary Jennejohn <gljennjohn at googlemail.com> wrote:
> > 
> > > It would be interesting to see your patch.  I always run HEAD but
> > > maybe I could use it as a base for my own mods/tests.
> > >
> > 
> > Here is the patch
> 
> This looks fair if all your disks are working at the same time (e.g.
> RAID only setup), but if you have a setup where you have multiple
> disks and only one is doing something, you limit the amount of tags
> which can be used. No idea what kind of performance impact this would
> have.
> 
> What about the case where you have more disks than tags?
> 
> I also noticed that you do a strncmp for "da". What about
> "ada" (available in 9 and 10), I would assume it suffers from the same
> problem.
> 

It seems to.  All my disks are ada.

-- 
Gary Jennejohn