Subject: Re: new MI/MD interface for rnd(4)
To: Colin Wood <>
From: Jason R Thorpe <>
List: tech-kern
Date: 06/05/2000 22:53:56
On Mon, Jun 05, 2000 at 05:50:12PM -0700, Colin Wood wrote:

 > Is a 32-bit number big enough?  On a sufficiently fast IA32 processor,
 > that counter (assuming you're using the timestamp counter) can overflow
 > within a relatively short period of time (4s on currently shipping
 > processors).  It is forseeable that it could overflow in less than a
 > second on processors shipping within the next few years. I don't know
 > enough about how often rnd.c samples, tho, so this might not be a
 > problem...

Not only that, but the TSC return value is 64-bit, right?  Also, the
Alpha `rpcc' intruction returns a 64-bit value, so I'd think this
would be 64-bit, at least.

        -- Jason R. Thorpe <>