RE: [PATCH 1/1] cciss per disk queue for 2.6

Miller, Mike (OS Dev)
2005-07-01T16:54:24Z

Jens Axboe wrote:
> Different thing, I'm talking about single volume starvation,
> not volume-to-volume.
>
> > elevator algoritm(s) may be causing writes to starve reads
> on the same
> > logical volume. We continue to investigate our other
> performance issues.
>
> I completely disagree. Even with an intelligent io scheduler,
> starvation is seen on ciss that does not happen on other
> queueing hardware such as 'normal' scsi controllers/drives.
> So something else is going on, and the only 'fix' so far is
> to limit the ciss queue depth heavily.

We will investigate this further and come up with a solution. Could be
the firmware, I suppose.

mikem

>
> --
> Jens Axboe
>
>