TC bfifo man page

Add back missing man page.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>

man/man8/tc-bfifo.8

+.TH PBFIFO 8 "10 January 2002" "iproute2" "Linux"
+.SH NAME
+pfifo \- Packet limited First In, First Out queue
+.P
+bfifo \- Byte limited First In, First Out queue
+
+.SH SYNOPSIS
+.B tc qdisc ... add pfifo
+.B [ limit 
+packets
+.B ]
+.P
+.B tc qdisc ... add bfifo
+.B [ limit 
+bytes
+.B ]
+
+.SH DESCRIPTION
+The pfifo and bfifo qdiscs are unadorned First In, First Out queues. They are the
+simplest queues possible and therefore have no overhead. 
+.B pfifo
+constrains the queue size as measured in packets. 
+.B bfifo
+does so as measured in bytes.
+
+Like all non-default qdiscs, they maintain statistics. This might be a reason to prefer 
+pfifo or bfifo over the default.
+
+.SH ALGORITHM
+A list of packets is maintained, when a packet is enqueued it gets inserted at the tail of
+a list. When a packet needs to be sent out to the network, it is taken from the head of the list. 
+
+If the list is too long, no further packets are allowed on. This is called 'tail drop'.
+
+.SH PARAMETERS
+.TP 
+limit
+Maximum queue size. Specified in bytes for bfifo, in packets for pfifo. For pfifo, defaults 
+to the interface txqueuelen, as specified with 
+.BR ifconfig (8)
+or
+.BR ip (8).
+
+For bfifo, it defaults to the txqueuelen multiplied by the interface MTU.
+
+.SH OUTPUT
+The output of 
+.B tc -s qdisc ls
+contains the limit, either in packets or in bytes, and the number of bytes 
+and packets actually sent. An unsent and dropped packet only appears between braces 
+and is not counted as 'Sent'.
+
+In this example, the queue length is 100 packets, 45894 bytes were sent over 681 packets. 
+No packets were dropped, and as the pfifo queue does not slow down packets, there were also no
+overlimits:
+.P
+.nf
+# tc -s qdisc ls dev eth0 
+qdisc pfifo 8001: dev eth0 limit 100p
+ Sent 45894 bytes 681 pkts (dropped 0, overlimits 0) 
+.fi
+
+If a backlog occurs, this is displayed as well.
+.SH SEE ALSO
+.BR tc (8)
+
+.SH AUTHORS
+Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>
+
+This manpage maintained by bert hubert <ahu@ds9a.nl>
+
+