arybchik 1d3e454e28 sfxge: fix overflow queue freeze
If TxQ lock is obtained, deferred packet list shold be serviced even if
the packet addition fails because of overflow.

Without the patch freeze happens if:
 - queue is not blocked (i.e. completion does not trigger unblock and service)
 - put-list overflow (1024 entries)
 - sfxge_tx_packet_add() acquires TxQ lock just as it is released it in
   sfxge_tx_qdpl_service() on the second CPU but before pending check
 - sfxge_tx_packet_add() swizzles put-list to get-list, fails because of
   non-tcp get-list overflow and returns without packet list service
 - sfxge_tx_qdpl_service() on the second CPU checks that there are no
   pending packets in the put-list and returns

Other possible solution is to guaranee that maximum length of the put-list
is less than maximum length of any get-list.

Reviewed by:    gnn
Sponsored by:   Solarflare Communications, Inc.
MFC after:      2 days
Differential Revision: https://reviews.freebsd.org/D2562
2015-05-18 06:02:22 +00:00
..
2015-05-16 20:06:39 +00:00
2015-01-23 15:14:30 +00:00
2015-03-23 19:47:52 +00:00
2015-01-30 01:13:07 +00:00
2015-02-24 01:00:46 +00:00
2015-03-08 19:55:46 +00:00
2015-04-22 14:38:58 +00:00
2015-01-23 15:14:30 +00:00
2015-01-23 15:14:30 +00:00
2015-04-03 11:37:23 +00:00
2015-05-16 05:59:25 +00:00
2014-09-28 07:40:26 +00:00
2015-05-15 06:11:47 +00:00
2015-04-29 20:08:03 +00:00
2014-10-10 14:17:42 +00:00
2014-10-11 19:36:59 +00:00
2015-03-23 19:47:52 +00:00
2015-04-22 14:38:58 +00:00
2014-12-03 00:47:05 +00:00
2014-11-18 21:58:57 +00:00
2014-09-19 03:55:19 +00:00
2015-05-18 06:02:22 +00:00
2015-03-23 19:47:52 +00:00
2014-11-21 21:34:19 +00:00
2014-11-20 20:09:18 +00:00