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

[Miller, Mike (OS Dev)]

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
> 
> 
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