sync the code with the version in head. which the exception of
svn 275358 (M_FLOWID deprecation, only a couple of lines)
which cannot be merged.

if_lem_netmap.h, if_re_netmap.h:
- use the same (commented out) function to update the stat counters
as in HEAD. This is a no-op here

netmap.c
- merge 274459 (support for private knote lock)
and minor changes on nm_config and comments

netmap_freebsd.c
- merge 274459 (support for private knote lock)
- merge 274354 (initialize color if passed as argument)

netmap_generic.c
- fix a comment

netmap_kern.h
- revise the lock macros, using sx locks;
merge 274459 (private knote lock)

netmap_monitor.c
- use full memory barriers

netmap_pipe.c
- use full memory barriers, use length from the correct queue
(mostly cosmetic, since the queues typically have the same size)

MFC r270253:
Change netmap's global lock to sx instead of a mutex.

MFC 270063: update of netmap code
(vtnet and cxgbe not merged yet because we need some other mfc first)

sync netmap code with the version in HEAD:
- fix handling of tx mbufs in emulated netmap mode;
- introduce mbq_lock() and mbq_unlock()
- rate limit some error messages
- many whitespace and comment fixes

MFH: sync the netmap code with the one in HEAD
(enhanced VALE switch, netmap pipes, emulated netmap mode).
See details in the log for svn 261909.

sync the code with the version in head. which the exception of
svn 275358 (M_FLOWID deprecation, only a couple of lines)
which cannot be merged.

if_lem_netmap.h, if_re_netmap.h:
- use the same (commented out) function to update the stat counters
as in HEAD. This is a no-op here

netmap.c
- merge 274459 (support for private knote lock)
and minor changes on nm_config and comments

netmap_freebsd.c
- merge 274459 (support for private knote lock)
- merge 274354 (initialize color if passed as argument)

netmap_generic.c
- fix a comment

netmap_kern.h
- revise the lock macros, using sx locks;
merge 274459 (private knote lock)

netmap_monitor.c
- use full memory barriers

netmap_pipe.c
- use full memory barriers, use length from the correct queue
(mostly cosmetic, since the queues typically have the same size)

MFC r270253:
Change netmap's global lock to sx instead of a mutex.

MFC 270063: update of netmap code
(vtnet and cxgbe not merged yet because we need some other mfc first)

sync netmap code with the version in HEAD:
- fix handling of tx mbufs in emulated netmap mode;
- introduce mbq_lock() and mbq_unlock()
- rate limit some error messages
- many whitespace and comment fixes

MFH: sync the netmap code with the one in HEAD
(enhanced VALE switch, netmap pipes, emulated netmap mode).
See details in the log for svn 261909.