K 10
svn:author
V 6
marius
K 8
svn:date
V 27
2014-04-30T14:09:26.767664Z
K 7
svn:log
V 1962
MFC: r241028

Change queue overflow checks from DIAGNOSTIC+panic() to KASSERT() to make
them enabled on HEAD by default. It is probably better to do single compare
then hunt for unexpected memory corruption.

MFC: r241444

Increase device CCB queue array size by CAM_RL_VALUES - 1 (4) elements.
It is required to store extra recovery requests in case of bus resets.
On ATA/SATA this fixes assertion panics on HEAD with INVARIANTS enabled or
possible memory corruptions otherwise if timeout/reset happens when device
CCB queue is already full.

MFC: r249466 (partial), r249438, r249481, r250025 (partial)

Remove multilevel freezing mechanism, implemented to handle specifics of
the ATA/SATA error recovery, when post-reset recovery commands should be
allocated when queues are already full of payload requests.  Instead of
removing frozen CCBs with specified range of priorities from the queue
to provide free openings, use simple hack, allowing explicit CCBs over-
allocation for requests with priority higher (numerically lower) then
CAM_PRIORITY_OOB threshold.

Simplify CCB allocation logic by removing SIM-level allocation queue.
After that SIM-level queue manages only CCBs execution, while allocation
logic is localized within each single device.

MFC: r253958

Change CCB queue resize logic to be able safely handle overallocations:
 - (re)allocate queue space in power of 2 chunks with 64 elements minimum
and never shrink it; with only 4/8 bytes per element size is insignificant.
 - automatically reallocate the queue to double size if it is overflowed.
 - if queue reallocation failed, store extra CCBs in unsorted TAILQ,
fetching them back as soon as some queue element is freed.

To free space in CCB for TAILQ linking, change highpowerq from keeping
high-power CCBs to keeping devices frozen due to high-power CCBs.

This encloses all pieces of queue resize logic inside of cam_queue.[ch],
removing some not obvious duties from xpt_release_ccb().

END