Subject: Performance tweak to Prefetch Abort path
To: None <>
From: Jason R Thorpe <>
List: port-arm
Date: 03/24/2002 17:59:15

I've just made another tweak to the ARM VM code, and this time
it should definitely improve performance.

In the Prefetch Abort path, the old code would make sure things looked
kosher, and then actually perform a data access on the faulting PC to
bring in the page.  While this had the desired effect, it meant that
we took a nother fault, for no good reason at all.

What I did was change the Prefetch Abort handler to do the UVM dance
directly, thus eliminating the second fault.

If you have any problems, please file a bug report.  That said, it works
fine on my StrongARM and XScale systems.

        -- Jason R. Thorpe <>