Re: an oops in 2.6-test2 (oops)

[Andrew Morton <akpm@osdl.org>]

"Marco d'Itri" <md@Linux.IT> wrote:
>
> I've got another one yesterday:
> 
> ...
> 
> Aug 16 07:26:51 wonderland kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
> ...
> Code;  c015c80a <find_inode_fast+1a/60>   <=====
>    0:   0f 18 02                  prefetchnta (%edx)   <=====

And you'll continue to get them until someone does something about it. 
Discussion seemed to die off on this problem.

Until it is sorted, something like this is needed.


diff -puN include/asm-i386/processor.h~disble-athlon-prefetch include/asm-i386/processor.h
--- 25/include/asm-i386/processor.h~disble-athlon-prefetch	2003-08-16 12:22:32.000000000 -0700
+++ 25-akpm/include/asm-i386/processor.h	2003-08-16 12:23:29.000000000 -0700
@@ -568,6 +568,8 @@ static inline void rep_nop(void)
 #define ARCH_HAS_PREFETCH
 extern inline void prefetch(const void *x)
 {
+	if (current_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		return;
 	alternative_input(ASM_NOP4,
 			  "prefetchnta (%1)",
 			  X86_FEATURE_XMM,

_