Merge randomdev_soft.c:1.5, 1.6, 1.7 from HEAD to RELENG_5:

2004-11-29T00:39:02Z

---------------------------- revision 1.7 date: 2004/11/03 10:02:50; author: rwatson; state: Exp; lines: +11 -14 (1) Move from O(n) list copies to O(1) list concatenation, which is supported for STAILQ via STAILQ_CONCAT(). (2) Maintain a count of the number of entries in the thread-local entropy fifo so that we can keep the other fifo counts in synch. MFC after: 3 weeks MFC with: randomdev_soft.c revisions 1.5 and 1.6 Suggested by: jhb (1) ---------------------------- revision 1.6 date: 2004/10/12 14:57:14; author: rwatson; state: Exp; lines: +6 -0 Assert that the entropy source category provided by a caller submitting entropy is valid, as an invalid source will cause dereferencing of an array of queues to an incorrect memory location. ---------------------------- revision 1.5 date: 2004/10/09 22:04:13; author: rwatson; state: Exp; lines: +41 -50 Modify entropy harvesting locking strategy: - Trade off granularity to reduce overhead, since the current model doesn't appear to reduce contention substantially: move to a single harvest mutex protecting harvesting queues, rather than one mutex per source plus a mutex for the free list. - Reduce mutex operations in a harvesting event to 2 from 4, and maintain lockless read to avoid mutex operations if the queue is full. - When reaping harvested entries from the queue, move all entries from the queue at once, and when done with them, insert them all into a thread-local queue for processing; then insert them all into the empty fifo at once. This reduces O(4n) mutex operations to O(2) mutex operations per wakeup. In the future, we may want to look at re-introducing granularity, although perhaps at the granularity of the source rather than the source class; both the new and old strategies would cause contention between different instances of the same source (i.e., multiple network interfaces). Reviewed by: markm Also merge subr_witness.c:1.182 from HEAD to RELENG_5: date: 2004/10/11 08:26:18; author: rwatson; state: Exp; lines: +1 -2 Add entropy harvest mutex to hard-coded spin lock witness lock order, remove previous entropy harvesting mutex names as they are no longer present. Commit to this file was ommitted when randomdev_soft.c:1.5 was made. Feet shot: Robert Huff

MFC: Don't adjust the random device kthread's priority to PUSER when

2004-11-24T16:06:02Z

sleeping.

Perform a lockless read to test whether an entropy havesting fifo is

2004-08-11T03:33:32Z

full, avoiding the cost of mutex operations if it is. We re-test once the mutex is acquired to make sure it's still true before doing the -modify-write part of the read-modify-write. Note that due to the maximum fifo depth being pretty deep, this is unlikely to improve harvesting performance yet. Approved by: markm

Start the entropy device insecure/unblocked. I'll be handing over

2004-07-18T09:07:58Z

responsibility for critical randomness requirements (like sshd) to rc.d/* Requested by: many

Default to harvesting everything. This is to help give a faster

2004-04-16T17:07:11Z

startup. harvesting can be turned OFF in etc/rc.d/* if it is a burden.

Reorganise the entropy device so that high-yield entropy sources

2004-04-09T15:47:10Z