Commit Graph

27 Commits

Author SHA1 Message Date
Felix Fietkau
eeafcb0c80 mac80211: minstrel_ht: remove old ewma based rate average code
The new noise filter has been the default for a while now with no reported
downside and significant improvement compared to the old code.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210115120242.89616-5-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-22 09:11:37 +01:00
Felix Fietkau
cbda98c710 mac80211: remove legacy minstrel rate control
Now that minstrel_ht supports legacy rates, it is no longer needed

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210115120242.89616-4-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-22 09:11:37 +01:00
Felix Fietkau
a7844a5384 mac80211: minstrel_ht: add support for OFDM rates on non-HT clients
The legacy minstrel code is essentially unmaintained and receives only very
little testing. In order to bring the significant algorithm improvements from
minstrel_ht to legacy clients, this patch adds support for OFDM rates to
minstrel_ht and removes the fallback to the legacy codepath.
This also makes it work much better on hardware with rate selection constraints,
e.g. mt76.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210115120242.89616-3-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-22 09:11:37 +01:00
Felix Fietkau
f84de06398 mac80211: minstrel_ht: clean up CCK code
- move ack overhead out of rate duration table
- remove cck_supported, cck_supported_short

Preparation for adding OFDM legacy rates support

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210115120242.89616-2-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-22 09:11:37 +01:00
Felix Fietkau
5f63afe028 mac80211: minstrel_ht: rename prob_ewma to prob_avg, use it for the new average
Reduces per-rate data structure size

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20191008171139.96476-3-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-10-11 10:31:45 +02:00
Felix Fietkau
48cb39522a mac80211: minstrel_ht: improve rate probing for devices with static fallback
On some devices that only support static rate fallback tables sending rate
control probing packets can be really expensive.
Probing lower rates can already hurt throughput quite a bit. What hurts even
more is the fact that on mt76x0/mt76x2, single probing packets can only be
forced by directing packets at a different internal hardware queue, which
causes some heavy reordering and extra latency.
The reordering issue is mainly problematic while pushing lots of packets to
a particular station. If there is little activity, the overhead of probing is
neglegible.

The static fallback behavior is designed to pretty much only handle rate
control algorithms that use only a very limited set of rates on which the
algorithm switches up/down based on packet error rate.

In order to better support that kind of hardware, this patch implements a
different approach to rate probing where it switches to a slightly higher rate,
waits for tx status feedback, then updates the stats and switches back to
the new max throughput rate. This only triggers above a packet rate of 100
per stats interval (~50ms).
For that kind of probing, the code has to reduce the set of probing rates
a lot more compared to single packet probing, so it uses only one packet
per MCS group which is either slightly faster, or as close as possible to
the max throughput rate.
This allows switching between similar rates with different numbers of
streams. The algorithm assumes that the hardware will work its way lower
within an MCS group in case of retransmissions, so that lower rates don't
have to be probed by the high packets per second rate probing code.

To further reduce the search space, it also does not probe rates with lower
channel bandwidth than the max throughput rate.

At the moment, these changes will only affect mt76x0/mt76x2.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20190820095449.45255-4-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-08-21 11:10:13 +02:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Felix Fietkau
7f2e12e1bf mac80211: minstrel_ht: add support for rates with 4 spatial streams
This is needed for the upcoming driver for MT7615 4x4 802.11ac chipsets

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00
Felix Fietkau
202df504d7 mac80211: minstrel: reduce minstrel_mcs_groups size
By storing a shift value for all duration values of a group, we can
reduce precision by a neglegible amount to make it fit into a u16 value.
This improves cache footprint and reduces size:

Before:
   text    data     bss     dec     hex filename
  10024     116       0   10140    279c rc80211_minstrel_ht.o

After:
   text    data     bss     dec     hex filename
   9368     116       0    9484    250c rc80211_minstrel_ht.o

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-10-11 16:01:02 +02:00
Felix Fietkau
b1c4f68337 mac80211: minstrel: merge with minstrel_ht, always enable VHT support
Legacy-only devices are not very common and the overhead of the extra
code for HT and VHT rates is not big enough to justify all those extra
lines of code to make it optional.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-10-11 16:01:01 +02:00
Felix Fietkau
5b5e87314e mac80211: minstrel: remove unnecessary debugfs cleanup code
debugfs entries are cleaned up by debugfs_remove_recursive already.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-10-11 16:01:00 +02:00
Felix Fietkau
41d085835d mac80211: minstrel_ht: move supported bitrate mask out of group data
Improves dcache footprint by ensuring that fewer cache lines need to be
touched.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-12-15 11:07:52 +01:00
Thomas Huehn
50e55a8ea7 mac80211: add max lossless throughput per rate
This patch adds the new statistic "maximum possible lossless
throughput" to Minstrels and Minstrel-HTs rc_stats (in debugfs). This
enables comprehensive comparison between current per-rate throughput
and max. achievable per-rate throughput.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-01 20:44:32 +02:00
Thomas Huehn
6a27b2c40b mac80211: restructure per-rate throughput calculation into function
This patch moves Minstrels and Minstrel-HTs per-rate throughput
calculation (EWMA(thr)) into a dedicated function to be called.
Therefore the variable "unsigned int cur_tp" within struct
"minstrel_rate_stats" becomes obsolete.  and is removed to free
up its space.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-01 20:44:32 +02:00
Thomas Huehn
9134073bc6 mac80211: improve Minstrel variable & function naming
This patch ensures a consistent usage of variable names for type
"minstrel_rate_stats" to be used as "mrs" and from type minstrel_rate
as "mr" across both Minstrel & Minstrel-HT. In addition some
variable and function names got changed to more meaningful ones.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-01 20:44:31 +02:00
Thomas Huehn
2cae0b6a70 mac80211: add new Minstrel-HT statistic output via csv
This patch adds a new debugfs file "rc_stats_csv" to output
Minstrel-HTs statistics in a common csv format that is easy
to parse.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Stefan Venz <ikstream86@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
[remove printing current time of day]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-01 20:44:26 +02:00
Karl Beldan
9208247d74 mac80211: minstrel_ht: add basic support for VHT rates <= 3SS@80MHz
When the new CONFIG_MAC80211_RC_MINSTREL_VHT is not set (default 'N'),
there is no behavioral change including in sampling and MCS_GROUP_RATES
remains 8.
Otherwise MCS_GROUP_RATES is 10, and a module parameter *vht_only*
(default 'true'), restricts the rates selection to VHT when VHT is
supported.

Regarding the debugfs stats buffer:
It is explicitly increased from 8k to 32k to fit every rates incl. when
both HT and VHT rates are enabled, as for the format, before:
type           rate     tpt eprob *prob ret  *ok(*cum)        ok(      cum)
HT20/LGI ABCDP MCS0     0.0   0.0   0.0   1    0(   0)         0(        0)
after:
 type           rate      tpt eprob *prob ret  *ok(*cum)        ok(      cum)
 HT20/LGI ABCDP MCS0      0.0   0.0   0.0   1    0(   0)         0(        0)
VHT40/LGI       MCS5/2    0.0   0.0   0.0   0    0(   0)         0(        0)

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-10-21 13:25:26 +02:00
Karl Beldan
8a0ee4fe19 mac80211: minstrel_ht: macros adjustments for future VHT_GROUPs
No functional change.

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-10-20 21:39:35 +02:00
Karl Beldan
d4d141cae8 mac80211: minstrel_ht: Increase the range of handled rate indexes
Since 5935839ad7 ("mac80211: improve minstrel_ht rate sorting by
throughput & probability"), the rate indexes are manipulated via u8's
and hence allow for a maximum of 256 mcs_group entries in
minstrel_mcs_groups.

ATM, minstrel_ht advertizes support up to 3HTSS@40MHz, consuming:
8(MCS_GROUP_RATES) * (3(SS)*2(GI)*2(BW)+1(CCK)), i.e. 104 entries.

Support for 3VHTSS@80MHz will require:
10(MCS_GROUP_RATES) * (3(SS)*2(GI)*2(BW)+1(CCK)) +
10(MCS_GROUP_RATES) * (3(SS)*2(GI)*3(BW)), i.e. 130 + 180 entries.

This change moves from u8s to u16s where necessary.

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-10-20 21:39:35 +02:00
Thomas Huehn
5935839ad7 mac80211: improve minstrel_ht rate sorting by throughput & probability
This patch improves the way minstrel_ht sorts rates according to throughput
and success probability. 3 FOR-loops across the entire rate and mcs group set
in function minstrel_ht_update_stats() which where used to determine the
fastest, second fastest and most robust rate are reduced to 2 FOR-loop.

The sorted list of rates according throughput is extended to the best four
rates as we need them in upcoming joint rate and power control. The sorting
is done via the new function minstrel_ht_sort_best_tp_rates(). The annotation
of those 4 best throughput rates in the debugfs file rc-stats is changes to:
"A,B,C,D", where A is the fastest rate and C the 4th fastest.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Tested-by: Stefan Venz <ikstream86@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-09-11 12:10:14 +02:00
Thomas Huehn
ca12c0c833 mac80211: Unify rate statistic variables between Minstrel & Minstrel_HT
Minstrel and Mintrel_HT used there own structs to keep track of rate
statistics. Unify those variables in struct minstrel_rate_states and
move it to rc80211_minstrel.h for common usage. This is a clean-up
patch to prepare Minstrel and Minstrel_HT codebase for upcoming TPC.

Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-09-11 12:08:31 +02:00
Felix Fietkau
a85666627b mac80211/minstrel_ht: use the new rate control API
Pass the rate selection table to mac80211 from minstrel_ht_update_stats.
Only rates for sample attempts are set in info->control.rates.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-04-22 16:16:41 +02:00
Thomas Huehn
c8ca8c2f93 mac80211: merge value scaling macros of minstrel_ht and minstrel
Both minstrel versions use individual ways to scale up integer values
to perform calculations. Merge minstrel_ht's scaling macros into
minstrels header file and use them in both minstrel versions.

Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06 16:36:07 +01:00
Felix Fietkau
965237ab9f mac80211/minstrel_ht: increase sampling frequency of some slower rates
If a rate is below the max_tp_rate, sample it frequently if:
- it is above max_tp_rate2, or
- it is above max_prob_rate and is a candidate for max_prob_rate
  (has fewer streams than max_tp_rate).
This helps the retry chain recover more quickly from bad statistics
caused by collisions or interference, and slightly reduces throughput
fluctuations with higher rates.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06 16:35:53 +01:00
Felix Fietkau
a0497f9f57 mac80211/minstrel_ht: add support for using CCK rates
When MCS rates start to get bad in 2.4 GHz because of long range or
strong interference, CCK rates can be a lot more robust.

This patch adds a pseudo MCS group containing CCK rates (long preamble
in the lower 4 slots, short preamble in the upper slots).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[make minstrel_ht_get_stats static]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-13 10:56:33 +01:00
John W. Linville
de66bfd85c minstrel_ht: move minstrel_mcs_groups declaration to header file
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
2010-06-24 15:42:18 -04:00
Felix Fietkau
ec8aa669b8 mac80211: add the minstrel_ht rate control algorithm
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-06-02 16:12:59 -04:00