"panic in 8.3-PRERELEASE" on Feb. 22, 2012. This panic was caused
by use of a mix of tsleep() and msleep() calls on the same event
in the new NFS server DRC code. It did "mtx_unlock(); tsleep();"
in two places, which kib@ noted introduced a slight risk that the
wakeup() would occur before the tsleep(), resulting in a 10sec
delay before waking up. This patch fixes the problem by replacing
"mtx_unlock(); tsleep();" with mtx_sleep(..PDROP..). It also
changes a nfsmsleep() call to mtx_sleep() so that the code uses
mtx_sleep() consistently within the file.
Tested by: hrs (in progress)
Reviewed by: jhb
MFC after: 5 days