linux/net/sched/Kconfig

#
# Traffic control configuration.
# 

menuconfig NET_SCHED
	bool "QoS and/or fair queueing"
	---help---
	  When the kernel has several packets to send out over a network
	  device, it has to decide which ones to send first, which ones to
	  delay, and which ones to drop. This is the job of the packet
	  scheduler, and several different algorithms for how to do this
	  "fairly" have been proposed.

	  If you say N here, you will get the standard packet scheduler, which
	  is a FIFO (first come, first served). If you say Y here, you will be
	  able to choose from among several alternative algorithms which can
	  then be attached to different network devices. This is useful for
	  example if some of your network devices are real time devices that
	  need a certain minimum data flow rate, or if you need to limit the
	  maximum data flow rate for traffic which matches specified criteria.
	  This code is considered to be experimental.

	  To administer these schedulers, you'll need the user-level utilities
	  from the package iproute2+tc at <ftp://ftp.tux.org/pub/net/ip-routing/>.
	  That package also contains some documentation; for more, check out
	  <http://snafu.freedom.org/linux2.2/iproute-notes.html>.

	  This Quality of Service (QoS) support will enable you to use
	  Differentiated Services (diffserv) and Resource Reservation Protocol
	  (RSVP) on your Linux router if you also say Y to "QoS support",
	  "Packet classifier API" and to some classifiers below. Documentation
	  and software is at <http://diffserv.sourceforge.net/>.

	  If you say Y here and to "/proc file system" below, you will be able
	  to read status information about packet schedulers from the file
	  /proc/net/psched.

	  The available schedulers are listed in the following questions; you
	  can say Y to as many as you like. If unsure, say N now.

choice
	prompt "Packet scheduler clock source"
	depends on NET_SCHED
	default NET_SCH_CLK_JIFFIES
	help
	  Packet schedulers need a monotonic clock that increments at a static
	  rate. The kernel provides several suitable interfaces, each with
	  different properties:
	  
	  - high resolution (us or better)
	  - fast to read (minimal locking, no i/o access)
	  - synchronized on all processors
	  - handles cpu clock frequency changes

	  but nothing provides all of the above.

config NET_SCH_CLK_JIFFIES
	bool "Timer interrupt"
	help
	  Say Y here if you want to use the timer interrupt (jiffies) as clock
	  source. This clock source is fast, synchronized on all processors and
	  handles cpu clock frequency changes, but its resolution is too low
	  for accurate shaping except at very low speed.

config NET_SCH_CLK_GETTIMEOFDAY
	bool "gettimeofday"
	help
	  Say Y here if you want to use gettimeofday as clock source. This clock
	  source has high resolution, is synchronized on all processors and
	  handles cpu clock frequency changes, but it is slow.

	  Choose this if you need a high resolution clock source but can't use
	  the CPU's cycle counter.

# don't allow on SMP x86 because they can have unsynchronized TSCs.
# gettimeofday is a good alternative
config NET_SCH_CLK_CPU
	bool "CPU cycle counter"
	depends on ((X86_TSC || X86_64) && !SMP) || ALPHA || SPARC64 || PPC64 || IA64
	help
	  Say Y here if you want to use the CPU's cycle counter as clock source.
	  This is a cheap and high resolution clock source, but on some
	  architectures it is not synchronized on all processors and doesn't
	  handle cpu clock frequency changes.

	  The useable cycle counters are:

	  	x86/x86_64	- Timestamp Counter
		alpha		- Cycle Counter
		sparc64		- %ticks register
		ppc64		- Time base
		ia64		- Interval Time Counter

	  Choose this if your CPU's cycle counter is working properly.

endchoice

config NET_SCH_CBQ
	tristate "CBQ packet scheduler"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to use the Class-Based Queueing (CBQ) packet
	  scheduling algorithm for some of your network devices.  This
	  algorithm classifies the waiting packets into a tree-like hierarchy
	  of classes; the leaves of this tree are in turn scheduled by
	  separate algorithms (called "disciplines" in this context).

	  See the top of <file:net/sched/sch_cbq.c> for references about the
	  CBQ algorithm.

	  CBQ is a commonly used scheduler, so if you're unsure, you should
	  say Y here. Then say Y to all the queueing algorithms below that you
	  want to use as CBQ disciplines.  Then say Y to "Packet classifier
	  API" and say Y to all the classifiers you want to use; a classifier
	  is a routine that allows you to sort your outgoing traffic into
	  classes based on a certain criterion.

	  To compile this code as a module, choose M here: the
	  module will be called sch_cbq.

config NET_SCH_HTB
	tristate "HTB packet scheduler"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to use the Hierarchical Token Buckets (HTB)
	  packet scheduling algorithm for some of your network devices. See
	  <http://luxik.cdi.cz/~devik/qos/htb/> for complete manual and
	  in-depth articles.

	  HTB is very similar to the CBQ regarding its goals however is has 
	  different properties and different algorithm.

	  To compile this code as a module, choose M here: the
	  module will be called sch_htb.

config NET_SCH_HFSC
	tristate "HFSC packet scheduler"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to use the Hierarchical Fair Service Curve
	  (HFSC) packet scheduling algorithm for some of your network devices.

	  To compile this code as a module, choose M here: the
	  module will be called sch_hfsc.

#tristate '  H-PFQ packet scheduler' CONFIG_NET_SCH_HPFQ
config NET_SCH_ATM
	tristate "ATM pseudo-scheduler"
	depends on NET_SCHED && ATM
	---help---
	  Say Y here if you want to use the ATM pseudo-scheduler.  This
	  provides a framework for invoking classifiers (aka "filters"), which
	  in turn select classes of this queuing discipline.  Each class maps
	  the flow(s) it is handling to a given virtual circuit (see the top of
	  <file:net/sched/sch_atm.c>).

	  To compile this code as a module, choose M here: the
	  module will be called sch_atm.

config NET_SCH_PRIO
	tristate "The simplest PRIO pseudoscheduler"
	depends on NET_SCHED
	help
	  Say Y here if you want to use an n-band priority queue packet
	  "scheduler" for some of your network devices or as a leaf discipline
	  for the CBQ scheduling algorithm. If unsure, say Y.

	  To compile this code as a module, choose M here: the
	  module will be called sch_prio.

config NET_SCH_RED
	tristate "RED queue"
	depends on NET_SCHED
	help
	  Say Y here if you want to use the Random Early Detection (RED)
	  packet scheduling algorithm for some of your network devices (see
	  the top of <file:net/sched/sch_red.c> for details and references
	  about the algorithm).

	  To compile this code as a module, choose M here: the
	  module will be called sch_red.

config NET_SCH_SFQ
	tristate "SFQ queue"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to use the Stochastic Fairness Queueing (SFQ)
	  packet scheduling algorithm for some of your network devices or as a
	  leaf discipline for the CBQ scheduling algorithm (see the top of
	  <file:net/sched/sch_sfq.c> for details and references about the SFQ
	  algorithm).

	  To compile this code as a module, choose M here: the
	  module will be called sch_sfq.

config NET_SCH_TEQL
	tristate "TEQL queue"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to use the True Link Equalizer (TLE) packet
	  scheduling algorithm for some of your network devices or as a leaf
	  discipline for the CBQ scheduling algorithm. This queueing
	  discipline allows the combination of several physical devices into
	  one virtual device. (see the top of <file:net/sched/sch_teql.c> for
	  details).

	  To compile this code as a module, choose M here: the
	  module will be called sch_teql.

config NET_SCH_TBF
	tristate "TBF queue"
	depends on NET_SCHED
	help
	  Say Y here if you want to use the Simple Token Bucket Filter (TBF)
	  packet scheduling algorithm for some of your network devices or as a
	  leaf discipline for the CBQ scheduling algorithm (see the top of
	  <file:net/sched/sch_tbf.c> for a description of the TBF algorithm).

	  To compile this code as a module, choose M here: the
	  module will be called sch_tbf.

config NET_SCH_GRED
	tristate "GRED queue"
	depends on NET_SCHED
	help
	  Say Y here if you want to use the Generic Random Early Detection
	  (GRED) packet scheduling algorithm for some of your network devices
	  (see the top of <file:net/sched/sch_red.c> for details and
	  references about the algorithm).

	  To compile this code as a module, choose M here: the
	  module will be called sch_gred.

config NET_SCH_DSMARK
	tristate "Diffserv field marker"
	depends on NET_SCHED
	help
	  Say Y if you want to schedule packets according to the
	  Differentiated Services architecture proposed in RFC 2475.
	  Technical information on this method, with pointers to associated
	  RFCs, is available at <http://www.gta.ufrj.br/diffserv/>.

	  To compile this code as a module, choose M here: the
	  module will be called sch_dsmark.

config NET_SCH_NETEM
	tristate "Network emulator"
	depends on NET_SCHED
	help
	  Say Y if you want to emulate network delay, loss, and packet
	  re-ordering. This is often useful to simulate networks when
	  testing applications or protocols.

	  To compile this driver as a module, choose M here: the module
	  will be called sch_netem.

	  If unsure, say N.

config NET_SCH_INGRESS
	tristate "Ingress Qdisc"
	depends on NET_SCHED 
	help
	  If you say Y here, you will be able to police incoming bandwidth
	  and drop packets when this bandwidth exceeds your desired rate.
	  If unsure, say Y.

	  To compile this code as a module, choose M here: the
	  module will be called sch_ingress.

config NET_QOS
	bool "QoS support"
	depends on NET_SCHED
	---help---
	  Say Y here if you want to include Quality Of Service scheduling
	  features, which means that you will be able to request certain
	  rate-of-flow limits for your network devices.

	  This Quality of Service (QoS) support will enable you to use
	  Differentiated Services (diffserv) and Resource Reservation Protocol
	  (RSVP) on your Linux router if you also say Y to "Packet classifier
	  API" and to some classifiers below. Documentation and software is at
	  <http://diffserv.sourceforge.net/>.

	  Note that the answer to this question won't directly affect the
	  kernel: saying N will just cause the configurator to skip all
	  the questions about QoS support.

config NET_ESTIMATOR
	bool "Rate estimator"
	depends on NET_QOS
	help
	  In order for Quality of Service scheduling to work, the current
	  rate-of-flow for a network device has to be estimated; if you say Y
	  here, the kernel will do just that.

config NET_CLS
	bool "Packet classifier API"
	depends on NET_SCHED
	---help---
	  The CBQ scheduling algorithm requires that network packets which are
	  scheduled to be sent out over a network device be classified
	  according to some criterion. If you say Y here, you will get a
	  choice of several different packet classifiers with the following
	  questions.

	  This will enable you to use Differentiated Services (diffserv) and
	  Resource Reservation Protocol (RSVP) on your Linux router.
	  Documentation and software is at
	  <http://diffserv.sourceforge.net/>.

config NET_CLS_BASIC
	tristate "Basic classifier"
	depends on NET_CLS
	---help---
	  Say Y here if you want to be able to classify packets using
	  only extended matches and actions.

	  To compile this code as a module, choose M here: the
	  module will be called cls_basic.

config NET_CLS_TCINDEX
	tristate "TC index classifier"
	depends on NET_CLS
	help
	  If you say Y here, you will be able to classify outgoing packets
	  according to the tc_index field of the skb. You will want this
	  feature if you want to implement Differentiated Services using
	  sch_dsmark. If unsure, say Y.

	  To compile this code as a module, choose M here: the
	  module will be called cls_tcindex.

config NET_CLS_ROUTE4
	tristate "Routing table based classifier"
	depends on NET_CLS
	select NET_CLS_ROUTE
	help
	  If you say Y here, you will be able to classify outgoing packets
	  according to the route table entry they matched. If unsure, say Y.

	  To compile this code as a module, choose M here: the
	  module will be called cls_route.

config NET_CLS_ROUTE
	bool
	default n

config NET_CLS_FW
	tristate "Firewall based classifier"
	depends on NET_CLS
	help
	  If you say Y here, you will be able to classify outgoing packets
	  according to firewall criteria you specified.

	  To compile this code as a module, choose M here: the
	  module will be called cls_fw.

config NET_CLS_U32
	tristate "U32 classifier"
	depends on NET_CLS
	help
	  If you say Y here, you will be able to classify outgoing packets
	  according to their destination address. If unsure, say Y.

	  To compile this code as a module, choose M here: the
	  module will be called cls_u32.

config CLS_U32_PERF
	bool "U32 classifier performance counters"
	depends on NET_CLS_U32
	help
	  gathers stats that could be used to tune u32 classifier performance.
	  Requires a new iproute2
	  You MUST NOT turn this on if you dont have an update iproute2.

config NET_CLS_IND
	bool "classify input device (slows things u32/fw) "
	depends on NET_CLS_U32 || NET_CLS_FW
	help
	  This option will be killed eventually when a 
          metadata action appears because it slows things a little
          Available only for u32 and fw classifiers.
	  Requires a new iproute2
	  You MUST NOT turn this on if you dont have an update iproute2.

config CLS_U32_MARK
	bool "Use nfmark as a key in U32 classifier"
	depends on NET_CLS_U32 && NETFILTER
	help
	  This allows you to match mark in a u32 filter.
	  Example:
	  tc filter add dev eth0 protocol ip parent 1:0 prio 5 u32 \
		match mark 0x0090 0xffff \
		match ip dst 4.4.4.4 \
		flowid 1:90
	  You must use a new iproute2 to use this feature.

config NET_CLS_RSVP
	tristate "Special RSVP classifier"
	depends on NET_CLS && NET_QOS
	---help---
	  The Resource Reservation Protocol (RSVP) permits end systems to
	  request a minimum and maximum data flow rate for a connection; this
	  is important for real time data such as streaming sound or video.

	  Say Y here if you want to be able to classify outgoing packets based
	  on their RSVP requests.

	  To compile this code as a module, choose M here: the
	  module will be called cls_rsvp.

config NET_CLS_RSVP6
	tristate "Special RSVP classifier for IPv6"
	depends on NET_CLS && NET_QOS
	---help---
	  The Resource Reservation Protocol (RSVP) permits end systems to
	  request a minimum and maximum data flow rate for a connection; this
	  is important for real time data such as streaming sound or video.

	  Say Y here if you want to be able to classify outgoing packets based
	  on their RSVP requests and you are using the new Internet Protocol
	  IPv6 as opposed to the older and more common IPv4.

	  To compile this code as a module, choose M here: the
	  module will be called cls_rsvp6.

config NET_EMATCH
	bool "Extended Matches"
	depends on NET_CLS
	---help---
	  Say Y here if you want to use extended matches on top of classifiers
	  and select the extended matches below.

	  Extended matches are small classification helpers not worth writing
	  a separate classifier.

	  You must have a recent version of the iproute2 tools in order to use
	  extended matches.

config NET_EMATCH_STACK
	int "Stack size"
	depends on NET_EMATCH
	default "32"
	---help---
	  Size of the local stack variable used while evaluating the tree of
	  ematches. Limits the depth of the tree, i.e. the number of
	  encapsulated precedences. Every level requires 4 bytes of additional
	  stack space.

config NET_EMATCH_CMP
	tristate "Simple packet data comparison"
	depends on NET_EMATCH
	---help---
	  Say Y here if you want to be able to classify packets based on
	  simple packet data comparisons for 8, 16, and 32bit values.

	  To compile this code as a module, choose M here: the
	  module will be called em_cmp.

config NET_EMATCH_NBYTE
	tristate "Multi byte comparison"
	depends on NET_EMATCH
	---help---
	  Say Y here if you want to be able to classify packets based on
	  multiple byte comparisons mainly useful for IPv6 address comparisons.

	  To compile this code as a module, choose M here: the
	  module will be called em_nbyte.

config NET_EMATCH_U32
	tristate "U32 hashing key"
	depends on NET_EMATCH
	---help---
	  Say Y here if you want to be able to classify packets using
	  the famous u32 key in combination with logic relations.

	  To compile this code as a module, choose M here: the
	  module will be called em_u32.

config NET_EMATCH_META
	tristate "Metadata"
	depends on NET_EMATCH
	---help---
	  Say Y here if you want to be ablt to classify packets based on
	  metadata such as load average, netfilter attributes, socket
	  attributes and routing decisions.

	  To compile this code as a module, choose M here: the
	  module will be called em_meta.

config NET_EMATCH_TEXT
	tristate "Textsearch"
	depends on NET_EMATCH
	select TEXTSEARCH
	select TEXTSEARCH_KMP
	select TEXTSEARCH_BM
	select TEXTSEARCH_FSM
	---help---
	  Say Y here if you want to be ablt to classify packets based on
	  textsearch comparisons.

	  To compile this code as a module, choose M here: the
	  module will be called em_text.

config NET_CLS_ACT
	bool "Packet ACTION"
	depends on EXPERIMENTAL && NET_CLS && NET_QOS
	---help---
	This option requires you have a new iproute2. It enables
	tc extensions which can be used with tc classifiers.
	  You MUST NOT turn this on if you dont have an update iproute2.

config NET_ACT_POLICE
	tristate "Policing Actions"
        depends on NET_CLS_ACT 
        ---help---
        If you are using a newer iproute2 select this one, otherwise use one
	below to select a policer.
	  You MUST NOT turn this on if you dont have an update iproute2.

config NET_ACT_GACT
        tristate "generic Actions"
        depends on NET_CLS_ACT
        ---help---
        You must have new iproute2 to use this feature.
        This adds simple filtering actions like drop, accept etc.

config GACT_PROB
        bool "generic Actions probability"
        depends on NET_ACT_GACT
        ---help---
        Allows generic actions to be randomly or deterministically used.

config NET_ACT_MIRRED
        tristate "Packet In/Egress redirecton/mirror Actions"
        depends on NET_CLS_ACT
        ---help---
        requires new iproute2
        This allows packets to be mirrored or redirected to netdevices

config NET_ACT_IPT
        tristate "iptables Actions"
        depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
        ---help---
        requires new iproute2
        This allows iptables targets to be used by tc filters

config NET_ACT_PEDIT
        tristate "Generic Packet Editor Actions"
        depends on NET_CLS_ACT
        ---help---
        requires new iproute2
        This allows for packets to be generically edited

config NET_CLS_POLICE
	bool "Traffic policing (needed for in/egress)"
	depends on NET_CLS && NET_QOS && NET_CLS_ACT!=y
	help
	  Say Y to support traffic policing (bandwidth limits).  Needed for
	  ingress and egress rate limiting.

config NET_ACT_SIMP
        tristate "Simple action"
        depends on NET_CLS_ACT
        ---help---
        You must have new iproute2 to use this feature.
        This adds a very simple action for demonstration purposes
	The idea is to give action authors a basic example to look at.
	All this action will do is print on the console the configured
	policy string followed by _ then packet count.