Re: Putrid Elevator Behavior 2.4.18/19

[Mike Fedyk]

On Wed, Mar 20, 2002 at 12:04:55PM -0700, Jeff V. Merkey wrote:
> 
> 
> 
> Jens/Linux,
> 
> The elevator code is malfunctioning in 2.4.18/19-pre when we start 
> reaching the upward limits with multiple 3Ware adapters 
> running together.  We started seeing the problem when we went to 
> 64 K aligned writes with sustained > 200 MB/S writes to 
> multiple 3Ware adapters.  
> 
> We have verified that the 3Ware adapters are not holding the request
> off, but that one of the requests is getting severely starved and
> does not get posted to the 3Ware adapters until thousands of IOs
> have gone before it.  
> 

This elevator starvation problem has been identified and a patch already
merged into 2.4.19-pre2.

Can you verify the affects it produces for your workload?