Re: queue_nr_requests needs to be selective

[Jeff V. Merkey]

On Fri, Mar 01, 2002 at 09:03:22PM +0000, Alan Cox wrote:
> > I don't immediately see why increasing the queue length should
> > increase bandwidth in this manner.  One possibility is that
> 
> Latency on the controllers ?  With caches on the controller and disks you
> can have a lot of requests actually in flight

Since 3ware uses a switched architecture, there are a lot of requests
in flight.  Can we get the default value increased or alternately, allow 
RAID drivers to submit a local queue_nr_request value per adapter 
so for those cards with 8 drives that make themselves look like
a single drive to Linux, sufficient buffers are available to prevent
threads feeding the device from going to sleep all the time?

:-)

Jeff