On Tue, 17 Oct 1995 09:27:04 -0700 (PDT) 
 devtrix@netcom.com (Matthew B. Wood) wrote:

 > Finally got current running (thanks Eric!) and recently recompiled my 
 > kernel.  I notcied that this line is still in the kernel config file:
 > 
 > 
 > #options        DUMMY_NOPS      # speed hack; recommended
 > 

I have this defined in all of my kernels ... However, I'll be damned if I 
can find any place where it makes a difference:

antie (thorpej) /sys/arch/i386/i386 473% grep DUMMY_NOPS *
locore.s:#ifdef DUMMY_NOPS      /* this will break some older machines */

...it's used to set up FASTER_NOP and NOP, which:

antie (thorpej) /sys/arch/i386/i386 476% grep NOP *
locore.s:#define        ALIGN_TEXT      .align  2,0x90  /* 4-byte 
boundaries, NOP-filled */
locore.s:/* NB: NOP now preserves registers so NOPs can be inserted 
anywhere */locore.s:/* XXX: NOP and FASTER_NOP are misleadingly named */
locore.s:#ifdef DUMMY_NOPS      /* this will break some older machines */
locore.s:#define        FASTER_NOP
locore.s:#define        NOP
locore.s:#define        FASTER_NOP      pushl %eax ; inb $0x84,%al ; popl 
%eax
locore.s:#define        NOP     pushl %eax ; inb $0x84,%al ; inb 
$0x84,%al ; popl %eax

*shrug*

--------------------------------------------------------------------------
Jason R. Thorpe                                       thorpej@nas.nasa.gov
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