bin/18114: iostat(8): msps from iostat is wrong

[arundel at FreeBSD.org]

Synopsis: iostat(8): msps from iostat is wrong

State-Changed-From-To: suspended->feedback
State-Changed-By: arundel
State-Changed-When: Tue Oct 5 21:05:01 UTC 2010
State-Changed-Why: 
After some research in connection with this PR I believe it can be closed.
Revision r81134 (from Aug 2001) switched from compute_stats(3) to
devstat_compute_statistics(3). With this change a lot of 'real' kernel stats
could be accessed from within iostat(8). One of these stats is:

"
     DSM_MS_PER_TRANSACTION_FREE     type: long double *

                                     The average duration of transactions of
                                     the specified type between the acquisi-
                                     tion of previous and current.
"

This means that 'msps' is now being derived from actual kernel stats and no
longer from 'tps'.
Since this is such an old PR and I'm not 100% sure I got this right, I'm keeping
it in feedback state until somebody can verify or falsify my assumption.

Cheers.
Alex

http://www.freebsd.org/cgi/query-pr.cgi?pr=18114