Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic

["Michael S. Zick" <lkml@morethan.org>]

On Fri May 22 2009, Samuel Thibault wrote:
> Michael S. Zick, le Fri 22 May 2009 14:53:39 -0500, a écrit :
> > Ref: http://developer.intel.com/Assets/PDF/manual/253666.pdf
> > Manual page: 3-590  PDF page: 638
> > Summary: Processors prior to P-4 can take an interrupt between
> > the read cycle and the write cycle. Which is why opcode 0xF0 exists.
> 
> Where do you see page 638/639 talking about interrupts?  It talks about
> multi-processor machines.
> 

No - it talks about "exclusive memory access" - You got bus master DMA
in your test machine? You also have an older than P-4 single processor?

Look people, I just reported what I found from testing - 
Please don't shoot the messanger.

If it: "Does not make a difference" then it "Should not make a difference"
but it does, try it yourself.  Its safe (if LOCK_PREFIX is in the proper
places) - the machine will ignore the opcode if is recent enough to not
need it - just trust the cpu's micro-code.

Mike
> Samuel
> 
>