Commit 7c34520b authored by Bjarni Ingi Gislason's avatar Bjarni Ingi Gislason Committed by Stephen Hemminger

tc(8): Negative indent and missing "-" after an escape

<groff: tc.8>:51: warning: total indent cannot be negative
<groff: tc.8>:57: warning: escape character ignored before `i'

*********************

Space at end of line removed

  General considerations

a) Manuals should usually only be left justified.  Use ".ad l"
as the first regular command.

b) Each sentence should begin on a new line.  The conventions
about the amount of space between sentences are different.  This
also makes a check on the number of space characters between
words easier.

c) Separate numbers from units with a (no-break) space.  A
no-break space can be code 0xA0, "\ " (\<space>), or "\~"
(groff).

d) Use macros "TS/TE" for tables with more than two columns.
Then use

'\" t

as the first line in the source to tell "man" to use the "tbl"
preprocessor.

e) Protect last period (full stop) in abbreviations with "\&",
if it is or might be (through new formatting of source) at the
end of line, if it is also not an end of sentence.

*********************

Originally filed at: http://bugs.debian.org/674704Signed-off-by: default avatarAndreas Henriksson <andreas@fatal.se>
parent 6fdd09d6
...@@ -2,22 +2,22 @@ ...@@ -2,22 +2,22 @@
.SH NAME .SH NAME
tc \- show / manipulate traffic control settings tc \- show / manipulate traffic control settings
.SH SYNOPSIS .SH SYNOPSIS
.B tc qdisc [ add | change | replace | link ] dev .B tc qdisc [ add | change | replace | link ] dev
DEV DEV
.B .B
[ parent [ parent
qdisc-id qdisc-id
.B | root ] .B | root ]
.B [ handle .B [ handle
qdisc-id ] qdisc qdisc-id ] qdisc
[ qdisc specific parameters ] [ qdisc specific parameters ]
.P .P
.B tc class [ add | change | replace ] dev .B tc class [ add | change | replace ] dev
DEV DEV
.B parent .B parent
qdisc-id qdisc-id
.B [ classid .B [ classid
class-id ] qdisc class-id ] qdisc
[ qdisc specific parameters ] [ qdisc specific parameters ]
.P .P
...@@ -36,38 +36,38 @@ flow-id ...@@ -36,38 +36,38 @@ flow-id
.B tc .B tc
.RI "[ " FORMAT " ]" .RI "[ " FORMAT " ]"
.B qdisc show [ dev .B qdisc show [ dev
DEV DEV
.B ] .B ]
.P .P
.B tc .B tc
.RI "[ " FORMAT " ]" .RI "[ " FORMAT " ]"
.B class show dev .B class show dev
DEV DEV
.P .P
.B tc filter show dev .B tc filter show dev
DEV DEV
.ti -8 .ti 8
.IR FORMAT " := {" .IR FORMAT " := {"
\fB\-s\fR[\fItatistics\fR] | \fB\-s\fR[\fItatistics\fR] |
\fB\-d\fR[\fIetails\fR] | \fB\-d\fR[\fIetails\fR] |
\fB\-r\fR[\fIaw\fR] | \fB\-r\fR[\fIaw\fR] |
\fB\-p\fR[\fIretty\fR] | \fB\-p\fR[\fIretty\fR] |
\fB\i\fR[\fIec\fR] } \fB\-i\fR[\fIec\fR] }
.SH DESCRIPTION .SH DESCRIPTION
.B Tc .B Tc
is used to configure Traffic Control in the Linux kernel. Traffic Control consists is used to configure Traffic Control in the Linux kernel. Traffic Control consists
of the following: of the following:
.TP .TP
SHAPING SHAPING
When traffic is shaped, its rate of transmission is under control. Shaping may When traffic is shaped, its rate of transmission is under control. Shaping may
be more than lowering the available bandwidth - it is also used to smooth out be more than lowering the available bandwidth - it is also used to smooth out
bursts in traffic for better network behaviour. Shaping occurs on egress. bursts in traffic for better network behaviour. Shaping occurs on egress.
.TP .TP
SCHEDULING SCHEDULING
By scheduling the transmission of packets it is possible to improve interactivity By scheduling the transmission of packets it is possible to improve interactivity
for traffic that needs it while still guaranteeing bandwidth to bulk transfers. Reordering for traffic that needs it while still guaranteeing bandwidth to bulk transfers. Reordering
...@@ -80,34 +80,34 @@ arriving. Policing thus occurs on ingress. ...@@ -80,34 +80,34 @@ arriving. Policing thus occurs on ingress.
.TP .TP
DROPPING DROPPING
Traffic exceeding a set bandwidth may also be dropped forthwith, both on Traffic exceeding a set bandwidth may also be dropped forthwith, both on
ingress and on egress. ingress and on egress.
.P .P
Processing of traffic is controlled by three kinds of objects: qdiscs, Processing of traffic is controlled by three kinds of objects: qdiscs,
classes and filters. classes and filters.
.SH QDISCS .SH QDISCS
.B qdisc .B qdisc
is short for 'queueing discipline' and it is elementary to is short for 'queueing discipline' and it is elementary to
understanding traffic control. Whenever the kernel needs to send a understanding traffic control. Whenever the kernel needs to send a
packet to an interface, it is packet to an interface, it is
.B enqueued .B enqueued
to the qdisc configured for that interface. Immediately afterwards, the kernel to the qdisc configured for that interface. Immediately afterwards, the kernel
tries to get as many packets as possible from the qdisc, for giving them tries to get as many packets as possible from the qdisc, for giving them
to the network adaptor driver. to the network adaptor driver.
A simple QDISC is the 'pfifo' one, which does no processing at all and is a pure A simple QDISC is the 'pfifo' one, which does no processing at all and is a pure
First In, First Out queue. It does however store traffic when the network interface First In, First Out queue. It does however store traffic when the network interface
can't handle it momentarily. can't handle it momentarily.
.SH CLASSES .SH CLASSES
Some qdiscs can contain classes, which contain further qdiscs - traffic may Some qdiscs can contain classes, which contain further qdiscs - traffic may
then be enqueued in any of the inner qdiscs, which are within the then be enqueued in any of the inner qdiscs, which are within the
.B classes. .B classes.
When the kernel tries to dequeue a packet from such a When the kernel tries to dequeue a packet from such a
.B classful qdisc .B classful qdisc
it can come from any of the classes. A qdisc may for example prioritize it can come from any of the classes. A qdisc may for example prioritize
certain kinds of traffic by trying to dequeue from certain classes certain kinds of traffic by trying to dequeue from certain classes
before others. before others.
...@@ -117,45 +117,45 @@ A ...@@ -117,45 +117,45 @@ A
is used by a classful qdisc to determine in which class a packet will is used by a classful qdisc to determine in which class a packet will
be enqueued. Whenever traffic arrives at a class with subclasses, it needs be enqueued. Whenever traffic arrives at a class with subclasses, it needs
to be classified. Various methods may be employed to do so, one of these to be classified. Various methods may be employed to do so, one of these
are the filters. All filters attached to the class are called, until one of are the filters. All filters attached to the class are called, until one of
them returns with a verdict. If no verdict was made, other criteria may be them returns with a verdict. If no verdict was made, other criteria may be
available. This differs per qdisc. available. This differs per qdisc.
It is important to notice that filters reside It is important to notice that filters reside
.B within .B within
qdiscs - they are not masters of what happens. qdiscs - they are not masters of what happens.
.SH CLASSLESS QDISCS .SH CLASSLESS QDISCS
The classless qdiscs are: The classless qdiscs are:
.TP .TP
[p|b]fifo [p|b]fifo
Simplest usable qdisc, pure First In, First Out behaviour. Limited in Simplest usable qdisc, pure First In, First Out behaviour. Limited in
packets or in bytes. packets or in bytes.
.TP .TP
pfifo_fast pfifo_fast
Standard qdisc for 'Advanced Router' enabled kernels. Consists of a three-band Standard qdisc for 'Advanced Router' enabled kernels. Consists of a three-band
queue which honors Type of Service flags, as well as the priority that may be queue which honors Type of Service flags, as well as the priority that may be
assigned to a packet. assigned to a packet.
.TP .TP
red red
Random Early Detection simulates physical congestion by randomly dropping Random Early Detection simulates physical congestion by randomly dropping
packets when nearing configured bandwidth allocation. Well suited to very packets when nearing configured bandwidth allocation. Well suited to very
large bandwidth applications. large bandwidth applications.
.TP .TP
sfq sfq
Stochastic Fairness Queueing reorders queued traffic so each 'session' Stochastic Fairness Queueing reorders queued traffic so each 'session'
gets to send a packet in turn. gets to send a packet in turn.
.TP .TP
tbf tbf
The Token Bucket Filter is suited for slowing traffic down to a precisely The Token Bucket Filter is suited for slowing traffic down to a precisely
configured rate. Scales well to large bandwidths. configured rate. Scales well to large bandwidths.
.SH CONFIGURING CLASSLESS QDISCS .SH CONFIGURING CLASSLESS QDISCS
In the absence of classful qdiscs, classless qdiscs can only be attached at In the absence of classful qdiscs, classless qdiscs can only be attached at
the root of a device. Full syntax: the root of a device. Full syntax:
.P .P
.B tc qdisc add dev .B tc qdisc add dev
DEV DEV
.B root .B root
QDISC QDISC-PARAMETERS QDISC QDISC-PARAMETERS
To remove, issue To remove, issue
...@@ -164,7 +164,7 @@ To remove, issue ...@@ -164,7 +164,7 @@ To remove, issue
DEV DEV
.B root .B root
The The
.B pfifo_fast .B pfifo_fast
qdisc is the automatic default in the absence of a configured qdisc. qdisc is the automatic default in the absence of a configured qdisc.
...@@ -172,85 +172,85 @@ qdisc is the automatic default in the absence of a configured qdisc. ...@@ -172,85 +172,85 @@ qdisc is the automatic default in the absence of a configured qdisc.
The classful qdiscs are: The classful qdiscs are:
.TP .TP
CBQ CBQ
Class Based Queueing implements a rich linksharing hierarchy of classes. Class Based Queueing implements a rich linksharing hierarchy of classes.
It contains shaping elements as well as prioritizing capabilities. Shaping is It contains shaping elements as well as prioritizing capabilities. Shaping is
performed using link idle time calculations based on average packet size and performed using link idle time calculations based on average packet size and
underlying link bandwidth. The latter may be ill-defined for some interfaces. underlying link bandwidth. The latter may be ill-defined for some interfaces.
.TP .TP
HTB HTB
The Hierarchy Token Bucket implements a rich linksharing hierarchy of The Hierarchy Token Bucket implements a rich linksharing hierarchy of
classes with an emphasis on conforming to existing practices. HTB facilitates classes with an emphasis on conforming to existing practices. HTB facilitates
guaranteeing bandwidth to classes, while also allowing specification of upper guaranteeing bandwidth to classes, while also allowing specification of upper
limits to inter-class sharing. It contains shaping elements, based on TBF and limits to inter-class sharing. It contains shaping elements, based on TBF and
can prioritize classes. can prioritize classes.
.TP .TP
PRIO PRIO
The PRIO qdisc is a non-shaping container for a configurable number of The PRIO qdisc is a non-shaping container for a configurable number of
classes which are dequeued in order. This allows for easy prioritization classes which are dequeued in order. This allows for easy prioritization
of traffic, where lower classes are only able to send if higher ones have of traffic, where lower classes are only able to send if higher ones have
no packets available. To facilitate configuration, Type Of Service bits are no packets available. To facilitate configuration, Type Of Service bits are
honored by default. honored by default.
.SH THEORY OF OPERATION .SH THEORY OF OPERATION
Classes form a tree, where each class has a single parent. Classes form a tree, where each class has a single parent.
A class may have multiple children. Some qdiscs allow for runtime addition A class may have multiple children. Some qdiscs allow for runtime addition
of classes (CBQ, HTB) while others (PRIO) are created with a static number of of classes (CBQ, HTB) while others (PRIO) are created with a static number of
children. children.
Qdiscs which allow dynamic addition of classes can have zero or more Qdiscs which allow dynamic addition of classes can have zero or more
subclasses to which traffic may be enqueued. subclasses to which traffic may be enqueued.
Furthermore, each class contains a Furthermore, each class contains a
.B leaf qdisc .B leaf qdisc
which by default has which by default has
.B pfifo .B pfifo
behaviour though another qdisc can be attached in place. This qdisc may again behaviour though another qdisc can be attached in place. This qdisc may again
contain classes, but each class can have only one leaf qdisc. contain classes, but each class can have only one leaf qdisc.
When a packet enters a classful qdisc it can be When a packet enters a classful qdisc it can be
.B classified .B classified
to one of the classes within. Three criteria are available, although not all to one of the classes within. Three criteria are available, although not all
qdiscs will use all three: qdiscs will use all three:
.TP .TP
tc filters tc filters
If tc filters are attached to a class, they are consulted first If tc filters are attached to a class, they are consulted first
for relevant instructions. Filters can match on all fields of a packet header, for relevant instructions. Filters can match on all fields of a packet header,
as well as on the firewall mark applied by ipchains or iptables. as well as on the firewall mark applied by ipchains or iptables.
.TP .TP
Type of Service Type of Service
Some qdiscs have built in rules for classifying packets based on the TOS field. Some qdiscs have built in rules for classifying packets based on the TOS field.
.TP .TP
skb->priority skb->priority
Userspace programs can encode a class-id in the 'skb->priority' field using Userspace programs can encode a class-id in the 'skb->priority' field using
the SO_PRIORITY option. the SO_PRIORITY option.
.P .P
Each node within the tree can have its own filters but higher level filters Each node within the tree can have its own filters but higher level filters
may also point directly to lower classes. may also point directly to lower classes.
If classification did not succeed, packets are enqueued to the leaf qdisc If classification did not succeed, packets are enqueued to the leaf qdisc
attached to that class. Check qdisc specific manpages for details, however. attached to that class. Check qdisc specific manpages for details, however.
.SH NAMING .SH NAMING
All qdiscs, classes and filters have IDs, which can either be specified All qdiscs, classes and filters have IDs, which can either be specified
or be automatically assigned. or be automatically assigned.
IDs consist of a major number and a minor number, separated by a colon. IDs consist of a major number and a minor number, separated by a colon.
.TP .TP
QDISCS QDISCS
A qdisc, which potentially can have children, A qdisc, which potentially can have children,
gets assigned a major number, called a 'handle', leaving the minor gets assigned a major number, called a 'handle', leaving the minor
number namespace available for classes. The handle is expressed as '10:'. number namespace available for classes. The handle is expressed as '10:'.
It is customary to explicitly assign a handle to qdiscs expected to have It is customary to explicitly assign a handle to qdiscs expected to have
children. children.
.TP .TP
CLASSES CLASSES
Classes residing under a qdisc share their qdisc major number, but each have Classes residing under a qdisc share their qdisc major number, but each have
a separate minor number called a 'classid' that has no relation to their a separate minor number called a 'classid' that has no relation to their
parent classes, only to their parent qdisc. The same naming custom as for parent classes, only to their parent qdisc. The same naming custom as for
qdiscs applies. qdiscs applies.
.TP .TP
FILTERS FILTERS
Filters have a three part ID, which is only needed when using a hashed Filters have a three part ID, which is only needed when using a hashed
filter hierarchy. filter hierarchy.
...@@ -258,7 +258,7 @@ filter hierarchy. ...@@ -258,7 +258,7 @@ filter hierarchy.
All parameters accept a floating point number, possibly followed by a unit. All parameters accept a floating point number, possibly followed by a unit.
.P .P
Bandwidths or rates can be specified in: Bandwidths or rates can be specified in:
.TP .TP
kbps kbps
Kilobytes per second Kilobytes per second
.TP .TP
...@@ -306,9 +306,9 @@ Microseconds. ...@@ -306,9 +306,9 @@ Microseconds.
The following commands are available for qdiscs, classes and filter: The following commands are available for qdiscs, classes and filter:
.TP .TP
add add
Add a qdisc, class or filter to a node. For all entities, a Add a qdisc, class or filter to a node. For all entities, a
.B parent .B parent
must be passed, either by passing its ID or by attaching directly to the root of a device. must be passed, either by passing its ID or by attaching directly to the root of a device.
When creating a qdisc or a filter, it can be named with the When creating a qdisc or a filter, it can be named with the
.B handle .B handle
parameter. A class is named with the parameter. A class is named with the
...@@ -317,15 +317,15 @@ parameter. ...@@ -317,15 +317,15 @@ parameter.
.TP .TP
remove remove
A qdisc can be removed by specifying its handle, which may also be 'root'. All subclasses and their leaf qdiscs A qdisc can be removed by specifying its handle, which may also be 'root'. All subclasses and their leaf qdiscs
are automatically deleted, as well as any filters attached to them. are automatically deleted, as well as any filters attached to them.
.TP .TP
change change
Some entities can be modified 'in place'. Shares the syntax of 'add', with the exception Some entities can be modified 'in place'. Shares the syntax of 'add', with the exception
that the handle cannot be changed and neither can the parent. In other words, that the handle cannot be changed and neither can the parent. In other words,
.B .B
change change
cannot move a node. cannot move a node.
.TP .TP
...@@ -335,7 +335,7 @@ it is created. ...@@ -335,7 +335,7 @@ it is created.
.TP .TP
link link
Only available for qdiscs and performs a replace where the node Only available for qdiscs and performs a replace where the node
must exist already. must exist already.
.SH FORMAT .SH FORMAT
......
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