2.6.9 iommu_alloc failures on PPC64

[Benjamin Herrenschmidt]

On Tue, 2004-10-26 at 16:33 -0700, Badari Pulavarty wrote:
> Hi,
> 
> When I run IO tests with 2.6.9 kernel on PPC64, I get hundreds of
> following messages and eventually get OOPS from qlogic driver.
> Is this a known problems ?
> 
> BTW, this happens only with JFS not ext3. 

I suppose JFS is flooding the driver with so many large requests that
the small table on your machine gets full (what machine is this
precisely ?).

The qlogic driver should be fixed to handle iommu failures more
gracefully. It should be possible in most cases to just wait for pending
IOs to complete & try again. I don't know if it's possible to ask the
upper layer to breakup the request.

Ben.