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2 .\" Written by: Kip Macy <kmacy@@FreeBSD.org>
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36 .Nm drbr_dequeue_cond ,
40 .Nm drbr_stats_update ,
41 .Nd network driver interface to buf_ring
47 .Fn drbr_free "struct buf_ring *br" "struct malloc_type *type"
49 .Fn drbr_enqueue "struct ifnet *ifp" "struct buf_ring *br" "struct mbuf *m"
51 .Fn drbr_dequeue "struct ifnet *ifp" "struct buf_ring *br"
53 .Fn drbr_dequeue_cond "struct ifnet *ifp" "struct buf_ring *br" "int (*func) (struct mbuf *, void *)" "void *arg"
55 .Fn drbr_flush "struct ifnet *ifp" "struct buf_ring *br"
57 .Fn drbr_empty "struct ifnet *ifp" "struct buf_ring *br"
59 .Fn drbr_inuse "struct ifnet *ifp" "struct buf_ring *br"
61 .Fn drbr_stats_update "struct ifnet *ifp" "int len" "int mflags"
65 functions provide an API to network drivers for using
67 for enqueueing and dequeueing packets.
68 This is meant as a replacement for the IFQ interface for packet queuing.
69 It allows a packet to be enqueued with a single atomic and packet
70 dequeue to be done without any per-packet atomics as it is protected
71 by the driver's tx queue lock.
76 will assert that the tx queue lock is held when it is called.
80 function frees all the enqueued mbufs and then frees the buf_ring.
84 function is used to enqueue an mbuf to a buf_ring, falling back to the
91 function is used to dequeue an mbuf from a buf_ring or, if
93 is enabled, from the ifnet's IFQ.
97 function is used to conditionally dequeue an mbuf from a buf_ring based
107 function frees all mbufs enqueued in the buf_ring and the ifnet's IFQ.
113 if there are no mbufs enqueued,
119 function returns the number of mbufs enqueued.
120 Note to users that this is intrinsically racy as there is no guarantee that
121 there will not be more mbufs when
124 Provided the tx queue lock is held there will not be less.
127 .Fn drbr_stats_update
128 function updates the number of bytes and the number of multicast packets sent.
134 if there are no slots available in the buf_ring and
141 .Fn drbr_dequeue_cond
142 functions return an mbuf on success and
144 if the buf_ring is empty.
146 These functions were introduced in