This patch adds the statistical descriptor "standard deviation"
to better describe the current properties of Minstrel and
Minstrel-HTs success probability distribution. The standard
deviation (SD) is calculated as exponential weighted moving
standard deviation (EWMSD) and its current value is added as
new column in all rc_stats (in debugfs).
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>
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>
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>
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>
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>
This patch restructures the rc_stats debugfs table of Minstrel-HT in
order to achieve better human readability. A new layout of the
statistics and a new header is added. In addition to the old layout
there are two new columns of information added:
idx - representing the rate index of each rate in mac80211 which
can be used to set specific rates as fixed rate via debugfs
airtime - the tx-time in micro seconds that a 1200 Byte packet
takes to be transmitted over the air at the given rate
The old layout of rc_stats:
type rate tpt eprob *prob ret *ok(*cum) ok( cum)
HT20/LGI MCS0 5.6 100.0 100.0 1 0( 0) 1( 1)
HT20/LGI B MCS1 10.5 100.0 100.0 0 0( 0) 1( 1)
HT20/LGI A MCS2 14.8 100.0 100.0 0 0( 0) 1( 1)
...
is changed into this new layout:
best ________rate______ __statistics__ ________last_______ ______sum-of________
mode guard # rate [name idx airtime] [ ø(tp) ø(prob)] [prob.|retry|suc|att] [#success | #attempts]
HT20 LGI 1 MCS0 0 1480 0.0 0.0 0.0 1 0 0 0 0
HT20 LGI 1 B MCS1 1 740 10.5 100.0 100.0 0 0 0 1 1
HT20 LGI 1 A MCS2 2 496 14.8 100.0 100.0 0 0 0 1 1
...
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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When displaying a rate through debugfs minstrel_ht guesses its flags
comparing group indexes. Since 3ec373c421 ("mac80211: minstrel_ht:
include type (cck/ht) in rates flag"), the rate flags of interest are
present in the mcs_group-s, so use it.
While improving the code, this also fixes a smatch false positive
"error: testing array offset 'i' after use" in minstrel_ht_stats_dump.
This warning only triggers after 9208247d74 ("mac80211: minstrel_ht:
add basic support for VHT rates <= 3SS@80MHz") with
CONFIG_MAC80211_RC_MINSTREL_VHT unset because then MINSTREL_VHT_GROUP_0
is above MINSTREL_GROUPS_NB and smatch only barks when the "testing
array offset" seems to prevent possible out of bonds accesses (which
does not happen here since i < ARRAY_SIZE(mi->groups)).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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>
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>
ATM an HT rc_stats line is 106 chars.
Times 8(MCS_GROUP_RATES)*3(SS)*2(GI)*2(BW) + CCK(4), i.e. x100, this is
well above the current 8192 - sizeof(*ms) currently allocated.
Fix this by squeezing the output as follows (not that we're short on
memory but this also improves readability and range, the new format adds
one more digit to *ok/*cum and ok/cum):
- Before (HT) (106 ch):
type rate throughput ewma prob this prob retry this succ/attempt success attempts
CCK/LP 5.5M 0.0 0.0 0.0 0 0( 0) 0 0
HT20/LGI ABCDP MCS0 0.0 0.0 0.0 1 0( 0) 0 0
- After (75 ch):
type rate tpt eprob *prob ret *ok(*cum) ok( cum)
CCK/LP 5.5M 0.0 0.0 0.0 0 0( 0) 0( 0)
HT20/LGI ABCDP MCS0 0.0 0.0 0.0 1 0( 0) 0( 0)
- Align non-HT format Before (non-HT) (83 ch):
rate throughput ewma prob this prob this succ/attempt success attempts
ABCDP 6 0.0 0.0 0.0 0( 0) 0 0
54 0.0 0.0 0.0 0( 0) 0 0
- After (61 ch):
rate tpt eprob *prob *ok(*cum) ok( cum)
ABCDP 1 0.0 0.0 0.0 0( 0) 0( 0)
54 0.0 0.0 0.0 0( 0) 0( 0)
*This also adds dynamic checks for overflow, lowers the size of the
non-HT request (allowing > 30 entries) and replaces the buddy-rounded
allocations (s/sizeof(*ms) + 8192/8192).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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>
Consecutive MCSes in [8*(NSS-1)->8*NSS[ have the same number NSS of
streams (except for MCS32 which is mishandled ATM).
ATM minstrel_ht uses MCS_GROUP_RATES in place of this 8 modulus.
This change replaces such occurences and by doing so allows for different
values of MCS_GROUP_RATES (e.g to cope with VHT MCS8,9).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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>
These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
