On 2/17/2011 3:23 PM, Rob van der Heij wrote:
On Thu, Feb 17, 2011 at 9:27 PM, Rich Greenberg<[email protected]> wrote:
Use the low order half of the TOD clock as a seed.
That does not have most entropy, at least for some models the lower
bytes don't change that often. There's probably value in combining the
two words or so. There used to be also the CPU number in the lower
bits, but I'm not sure that is still needed on modern CPUs.
The CPU number was/is there so that different CPUs having independent
TOD clocks could be guaranteed unique results. The ETOD has a similar
field, now in a register specifiable by the (systems) programmer.
I don't know how SIE affects it.
Probably a good way to "[combine] the two words or so" is with a
hash algorithm. Mix in barometric pressure and phase of moon to
taste.
-- gil
