Commit c21b39ac authored by Stefano Brivio's avatar Stefano Brivio Committed by David S. Miller
Browse files

mac80211: make PID rate control algorithm the default 



This makes the new PID TX rate control algorithm the default instead of the
rc80211_simple rate control algorithm. The simple algorithm was flawed in
several ways: it wasn't responsive at all and didn't age the information it was
relying on properly. The PID algorithm allows us to tune characteristics such
as responsiveness by adjusting parameters and was found to generally behave
better.

The default algorithm can be overridden to select simple instead. Which
ever algorithm is the default is included as part of the mac80211
module automatically. The other algorithm (simple vs. pid) can
be selected for inclusion as well. If EMBEDDED is selected then
the choice is available to have no default specified and neither
algorithm included in mac80211. The default algorithm can be set
through a modparam.

While at it, mark rc80211-simple as deprecated, and schedule it
for removal.

Signed-off-by: default avatarStefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b92edbe0

Documentation/feature-removal-schedule.txt

+8 −0
Original line number Diff line number Diff line
@@ -314,3 +314,11 @@ Why: No in-kernel drivers will depend on it any longer. 
Who:	John W. Linville <linville@tuxdriver.com>



---------------------------



What:	rc80211-simple rate control algorithm for mac80211

When:	2.6.26

Files:	net/mac80211/rc80211-simple.c

Why:	This algorithm was provided for reference but always exhibited bad

	responsiveness and performance and has some serious flaws. It has been

	replaced by rc80211-pid.

Who:	Stefano Brivio <stefano.brivio@polimi.it>

net/mac80211/Kconfig

+59 −13
Original line number Diff line number Diff line
@@ -13,29 +13,75 @@ config MAC80211 
	This option enables the hardware independent IEEE 802.11

	networking stack.



config MAC80211_RCSIMPLE

	bool "'simple' rate control algorithm" if EMBEDDED

config MAC80211_RC_DEFAULT_CHOICE

	bool "Choose default rate control algorithm" if EMBEDDED

	default y

	depends on MAC80211

	help

	  This option allows you to turn off the 'simple' rate

	  control algorithm in mac80211. If you do turn it off,

	  you absolutely need another rate control algorithm.

	---help---

	  This options enables selection of a default rate control

	  algorithm to be built into the mac80211 module.  Alternate

	  rate control algorithms might be built into the mac80211

	  module as well.



choice

	prompt "Default rate control algorithm"

	default MAC80211_RC_DEFAULT_PID

	depends on MAC80211 && MAC80211_RC_DEFAULT_CHOICE

	---help---

	  This option selects the default rate control algorithm

	  mac80211 will use. Note that this default can still be

	  overriden through the ieee80211_default_rc_algo module

	  parameter.



config MAC80211_RC_DEFAULT_PID

	bool "PID controller based rate control algorithm"

	select MAC80211_RC_PID

	---help---

	  Select the PID controller based rate control as the

	  default rate control algorithm. You should choose

	  this unless you know what you are doing.



config MAC80211_RC_DEFAULT_SIMPLE

	bool "Simple rate control algorithm"

	select MAC80211_RC_SIMPLE

	---help---

	  Select the simple rate control as the default rate

	  control algorithm. Note that this is a non-responsive,

	  dumb algorithm. You should choose the PID rate control

	  instead.



endchoice



	  Say Y unless you know you will have another algorithm

	  available.

config MAC80211_RC_DEFAULT

	string

	depends on MAC80211

	default "pid" if MAC80211_RC_DEFAULT_PID

	default "simple" if MAC80211_RC_DEFAULT_SIMPLE

	default ""



config MAC80211_RCPID

	bool "'PID' rate control algorithm" if EMBEDDED

config MAC80211_RC_PID

	bool "PID controller based rate control algorithm"

	default y

	depends on MAC80211

	help

	---help---

	  This option enables a TX rate control algorithm for

	  mac80211 that uses a PID controller to select the TX

	  rate.



	  Say Y unless you're sure you want to use a different

	  rate control algorithm.

	  Say Y or M unless you're sure you want to use a

	  different rate control algorithm.



config MAC80211_RC_SIMPLE

	bool "Simple rate control algorithm (DEPRECATED)"

	default n

	depends on MAC80211

	---help---

	  This option enables a very simple, non-responsive TX

	  rate control algorithm. This algorithm is deprecated

	  and will be removed from the kernel in near future.

	  It has been replaced by the PID algorithm.



	  Say N unless you know what you are doing.



config MAC80211_LEDS

	bool "Enable LED triggers"

net/mac80211/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -3,8 +3,8 @@ obj-$(CONFIG_MAC80211) += mac80211.o 
mac80211-objs-$(CONFIG_MAC80211_LEDS) += ieee80211_led.o

mac80211-objs-$(CONFIG_MAC80211_DEBUGFS) += debugfs.o debugfs_sta.o debugfs_netdev.o debugfs_key.o

mac80211-objs-$(CONFIG_NET_SCHED) += wme.o

mac80211-objs-$(CONFIG_MAC80211_RCSIMPLE) += rc80211_simple.o

mac80211-objs-$(CONFIG_MAC80211_RCPID) += rc80211_pid.o

mac80211-objs-$(CONFIG_MAC80211_RC_SIMPLE) += rc80211_simple.o

mac80211-objs-$(CONFIG_MAC80211_RC_PID) += rc80211_pid.o



mac80211-objs := \

	ieee80211.o \

net/mac80211/ieee80211.c

+6 −6
Original line number Diff line number Diff line
@@ -1312,13 +1312,13 @@ static int __init ieee80211_init(void) 


	BUILD_BUG_ON(sizeof(struct ieee80211_tx_packet_data) > sizeof(skb->cb));



#ifdef CONFIG_MAC80211_RCSIMPLE

#ifdef CONFIG_MAC80211_RC_SIMPLE

	ret = ieee80211_rate_control_register(&mac80211_rcsimple);

	if (ret)

		goto fail;

#endif



#ifdef CONFIG_MAC80211_RCPID

#ifdef CONFIG_MAC80211_RC_PID

	ret = ieee80211_rate_control_register(&mac80211_rcpid);

	if (ret)

		goto fail;
@@ -1338,10 +1338,10 @@ static int __init ieee80211_init(void) 


fail:



#ifdef CONFIG_MAC80211_RCSIMPLE

#ifdef CONFIG_MAC80211_RC_SIMPLE

	ieee80211_rate_control_unregister(&mac80211_rcsimple);

#endif

#ifdef CONFIG_MAC80211_RCPID

#ifdef CONFIG_MAC80211_RC_PID

	ieee80211_rate_control_unregister(&mac80211_rcpid);

#endif
@@ -1350,10 +1350,10 @@ fail: 


static void __exit ieee80211_exit(void)

{

#ifdef CONFIG_MAC80211_RCSIMPLE

#ifdef CONFIG_MAC80211_RC_SIMPLE

	ieee80211_rate_control_unregister(&mac80211_rcsimple);

#endif

#ifdef CONFIG_MAC80211_RCPID

#ifdef CONFIG_MAC80211_RC_PID

	ieee80211_rate_control_unregister(&mac80211_rcpid);

#endif

net/mac80211/ieee80211_rate.c

+18 −6
Original line number Diff line number Diff line
@@ -21,6 +21,11 @@ struct rate_control_alg { 
static LIST_HEAD(rate_ctrl_algs);

static DEFINE_MUTEX(rate_ctrl_mutex);



static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;

module_param(ieee80211_default_rc_algo, charp, 0644);

MODULE_PARM_DESC(ieee80211_default_rc_algo,

		 "Default rate control algorithm for mac80211 to use");



int ieee80211_rate_control_register(struct rate_control_ops *ops)

{

	struct rate_control_alg *alg;
@@ -89,21 +94,27 @@ ieee80211_try_rate_control_ops_get(const char *name) 
	return ops;

}



/* Get the rate control algorithm. If `name' is NULL, get the first

 * available algorithm. */

/* Get the rate control algorithm. */

static struct rate_control_ops *

ieee80211_rate_control_ops_get(const char *name)

{

	struct rate_control_ops *ops;

	const char *alg_name;



	if (!name)

		name = "simple";

		alg_name = ieee80211_default_rc_algo;

	else

		alg_name = name;



	ops = ieee80211_try_rate_control_ops_get(name);

	ops = ieee80211_try_rate_control_ops_get(alg_name);

	if (!ops) {

		request_module("rc80211_%s", name);

		ops = ieee80211_try_rate_control_ops_get(name);

		request_module("rc80211_%s", alg_name);

		ops = ieee80211_try_rate_control_ops_get(alg_name);

	}

	if (!ops && name)

		/* try default if specific alg requested but not found */

		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);



	return ops;

}
@@ -244,3 +255,4 @@ void rate_control_deinitialize(struct ieee80211_local *local) 
	local->rate_ctrl = NULL;

	rate_control_put(ref);

}

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