CAM disk I/O starvation
Alexander at Leidinger.net
Thu Apr 5 03:23:16 UTC 2012
On Tue, 3 Apr 2012 14:27:43 -0700 Jerry Toung <jrytoung at gmail.com>
> 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
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
http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137
More information about the freebsd-hackers