K 10
svn:author
V 3
avg
K 8
svn:date
V 27
2013-07-09T09:01:44.852311Z
K 7
svn:log
V 407
should_yield: protect from td_swvoltick being uninitialized or too stale

The distance between ticks and td_swvoltick should be calculated as
an unsigned number.  Previously we could end up comparing a negative
number with hogticks in which case should_yield() would give incorrect
answer.

We should probably ensure that td_swvoltick is properly initialized.

Sponsored by:	HybridCluster
MFC after:	5 days

END