Subject: Re: new MI/MD interface for rnd(4)
To: Colin Wood <>
From: Jason R Thorpe <>
List: tech-kern
Date: 06/06/2000 15:19:14
On Tue, Jun 06, 2000 at 02:13:12PM -0700, Colin Wood wrote:

 > yes, RDTSC should return a 64-bit number.  hopefully these new routines
 > are picking the proper 32 bits as the upper 32 bits (in EDX) only change
 > every few seconds.  if bill is just trying to read some random value, then
 i guess only using the lower 32 bits is fine.  relying on only 32-bits as

What `rnd' should be doing then is reading the 64-bit cycle counter
and then making off the top 32-bits, i.e.:

	rndval = cpu_counter() & 0xffffffffUL;

        -- Jason R. Thorpe <>