Subject: Re: Kernel copyin/out optimizations for ARM...
To: David Laight <david@l8s.co.uk>
From: Jason R Thorpe <thorpej@wasabisystems.com>
List: port-arm
Date: 03/16/2002 22:27:03
On Sat, Mar 16, 2002 at 04:47:19PM -0800, Jason R Thorpe wrote:

 > Well, it doesn't work :-)
 > 
 > First of all, I had to futz with the numbered-labels.  Our ELF assembler
 > does like e.g. 11$.  I'm pretty sure I got the translation to gas-style
 > numbered-labels right :-)
 > 
 > Secondly, after managing to fork a few processes on an SA-110, it
 > croaks:
 > 
 > panic: kernel diagnostic assertion "umap->refcount != 0" failed: file "/u1/netbsd/src/sys/arch/shark/compile/SHAG-SHARK/../../../../uvm/uvm_bio.c", line 253
 > 
 > Looks like it's not honoring write-protection properly somewhere.

More info --- if you force it to use user perms always, it works, but
is seemingly much slower than the original.

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>