From: David Mosberger <davidm@napali.hpl.hp.com>

Somebody recently pointed out a performance-anomaly to me where an unusual
amount of time was being spent reading from /dev/urandom.  The problem
isn't really surprising as it happened only on >= 4-way machines and the
random driver isn't terribly scalable the way it is written today.  If
scalability _really_ mattered, I suppose per-CPU data structures would be
the way to go.  However, I found that at least for 4-way machines,
performance can be improved considerably with the attached patch.  In
particular, I saw the following performance on a 4-way ia64 machine:

Test: 3 tasks running "dd if=/dev/urandom of=/dev/null bs=1024":

			throughput: