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Commit 202df504 authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
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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: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent b1c4f683

net/mac80211/rc80211_minstrel_ht.c

+80 −73
Original line number Diff line number Diff line
@@ -52,22 +52,23 @@ 
	_streams - 1



/* MCS rate information for an MCS group */

#define MCS_GROUP(_streams, _sgi, _ht40)				\

#define MCS_GROUP(_streams, _sgi, _ht40, _s)				\

	[GROUP_IDX(_streams, _sgi, _ht40)] = {				\

	.streams = _streams,						\

	.shift = _s,							\

	.flags =							\

		IEEE80211_TX_RC_MCS |					\

		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\

		(_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),		\

	.duration = {							\

		MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26),		\

		MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52),		\

		MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78),		\

		MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104),	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156),	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208),	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234),	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260)		\

		MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s,	\

		MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s	\

	}								\

}
@@ -80,9 +81,10 @@ 
#define BW2VBPS(_bw, r3, r2, r1)					\

	(_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)



#define VHT_GROUP(_streams, _sgi, _bw)					\

#define VHT_GROUP(_streams, _sgi, _bw, _s)				\

	[VHT_GROUP_IDX(_streams, _sgi, _bw)] = {			\

	.streams = _streams,						\

	.shift = _s,							\

	.flags =							\

		IEEE80211_TX_RC_VHT_MCS |				\

		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
@@ -90,25 +92,25 @@ 
		 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),	\

	.duration = {							\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  117,  54,  26)),		\

			     BW2VBPS(_bw,  117,  54,  26)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  234, 108,  52)),		\

			     BW2VBPS(_bw,  234, 108,  52)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  351, 162,  78)),		\

			     BW2VBPS(_bw,  351, 162,  78)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  468, 216, 104)),		\

			     BW2VBPS(_bw,  468, 216, 104)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  702, 324, 156)),		\

			     BW2VBPS(_bw,  702, 324, 156)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw,  936, 432, 208)),		\

			     BW2VBPS(_bw,  936, 432, 208)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw, 1053, 486, 234)),		\

			     BW2VBPS(_bw, 1053, 486, 234)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw, 1170, 540, 260)),		\

			     BW2VBPS(_bw, 1170, 540, 260)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw, 1404, 648, 312)),		\

			     BW2VBPS(_bw, 1404, 648, 312)) >> _s,	\

		MCS_DURATION(_streams, _sgi,				\

			     BW2VBPS(_bw, 1560, 720, 346))		\

			     BW2VBPS(_bw, 1560, 720, 346)) >> _s	\

	}								\

}
@@ -121,19 +123,20 @@ 
	(CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) +	\

	 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))



#define CCK_DURATION_LIST(_short)			\

	CCK_ACK_DURATION(10, _short),			\

	CCK_ACK_DURATION(20, _short),			\

	CCK_ACK_DURATION(55, _short),			\

	CCK_ACK_DURATION(110, _short)

#define CCK_DURATION_LIST(_short, _s)			\

	CCK_ACK_DURATION(10, _short) >> _s,		\

	CCK_ACK_DURATION(20, _short) >> _s,		\

	CCK_ACK_DURATION(55, _short) >> _s,		\

	CCK_ACK_DURATION(110, _short) >> _s



#define CCK_GROUP					\

#define CCK_GROUP(_s)					\

	[MINSTREL_CCK_GROUP] = {			\

		.streams = 0,				\

		.flags = 0,				\

		.shift = _s,				\

		.duration = {				\

			CCK_DURATION_LIST(false),	\

			CCK_DURATION_LIST(true)		\

			CCK_DURATION_LIST(false, _s),	\

			CCK_DURATION_LIST(true, _s)	\

		}					\

	}
@@ -151,47 +154,47 @@ MODULE_PARM_DESC(minstrel_vht_only, 
 * BW -> SGI -> #streams

 */

const struct mcs_group minstrel_mcs_groups[] = {

	MCS_GROUP(1, 0, BW_20),

	MCS_GROUP(2, 0, BW_20),

	MCS_GROUP(3, 0, BW_20),

	MCS_GROUP(1, 0, BW_20, 5),

	MCS_GROUP(2, 0, BW_20, 4),

	MCS_GROUP(3, 0, BW_20, 4),



	MCS_GROUP(1, 1, BW_20),

	MCS_GROUP(2, 1, BW_20),

	MCS_GROUP(3, 1, BW_20),

	MCS_GROUP(1, 1, BW_20, 5),

	MCS_GROUP(2, 1, BW_20, 4),

	MCS_GROUP(3, 1, BW_20, 4),



	MCS_GROUP(1, 0, BW_40),

	MCS_GROUP(2, 0, BW_40),

	MCS_GROUP(3, 0, BW_40),

	MCS_GROUP(1, 0, BW_40, 4),

	MCS_GROUP(2, 0, BW_40, 4),

	MCS_GROUP(3, 0, BW_40, 4),



	MCS_GROUP(1, 1, BW_40),

	MCS_GROUP(2, 1, BW_40),

	MCS_GROUP(3, 1, BW_40),

	MCS_GROUP(1, 1, BW_40, 4),

	MCS_GROUP(2, 1, BW_40, 4),

	MCS_GROUP(3, 1, BW_40, 4),



	CCK_GROUP,

	CCK_GROUP(8),



	VHT_GROUP(1, 0, BW_20),

	VHT_GROUP(2, 0, BW_20),

	VHT_GROUP(3, 0, BW_20),

	VHT_GROUP(1, 0, BW_20, 5),

	VHT_GROUP(2, 0, BW_20, 4),

	VHT_GROUP(3, 0, BW_20, 4),



	VHT_GROUP(1, 1, BW_20),

	VHT_GROUP(2, 1, BW_20),

	VHT_GROUP(3, 1, BW_20),

	VHT_GROUP(1, 1, BW_20, 5),

	VHT_GROUP(2, 1, BW_20, 4),

	VHT_GROUP(3, 1, BW_20, 4),



	VHT_GROUP(1, 0, BW_40),

	VHT_GROUP(2, 0, BW_40),

	VHT_GROUP(3, 0, BW_40),

	VHT_GROUP(1, 0, BW_40, 4),

	VHT_GROUP(2, 0, BW_40, 4),

	VHT_GROUP(3, 0, BW_40, 4),



	VHT_GROUP(1, 1, BW_40),

	VHT_GROUP(2, 1, BW_40),

	VHT_GROUP(3, 1, BW_40),

	VHT_GROUP(1, 1, BW_40, 4),

	VHT_GROUP(2, 1, BW_40, 4),

	VHT_GROUP(3, 1, BW_40, 4),



	VHT_GROUP(1, 0, BW_80),

	VHT_GROUP(2, 0, BW_80),

	VHT_GROUP(3, 0, BW_80),

	VHT_GROUP(1, 0, BW_80, 4),

	VHT_GROUP(2, 0, BW_80, 4),

	VHT_GROUP(3, 0, BW_80, 4),



	VHT_GROUP(1, 1, BW_80),

	VHT_GROUP(2, 1, BW_80),

	VHT_GROUP(3, 1, BW_80),

	VHT_GROUP(1, 1, BW_80, 4),

	VHT_GROUP(2, 1, BW_80, 4),

	VHT_GROUP(3, 1, BW_80, 4),

};



static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
@@ -307,7 +310,8 @@ minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 
	if (group != MINSTREL_CCK_GROUP)

		nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);



	nsecs += minstrel_mcs_groups[group].duration[rate];

	nsecs += minstrel_mcs_groups[group].duration[rate] <<

		 minstrel_mcs_groups[group].shift;



	/*

	 * For the throughput calculation, limit the probability value to 90% to
@@ -755,12 +759,19 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 
		minstrel_ht_update_rates(mp, mi);

}



static inline int

minstrel_get_duration(int index)

{

	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];

	unsigned int duration = group->duration[index % MCS_GROUP_RATES];

	return duration << group->shift;

}



static void

minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,

                         int index)

{

	struct minstrel_rate_stats *mrs;

	const struct mcs_group *group;

	unsigned int tx_time, tx_time_rtscts, tx_time_data;

	unsigned int cw = mp->cw_min;

	unsigned int ctime = 0;
@@ -779,8 +790,7 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
	mrs->retry_count_rtscts = 2;

	mrs->retry_updated = true;



	group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];

	tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;

	tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;



	/* Contention time for first 2 tries */

	ctime = (t_slot * cw) >> 1;
@@ -874,20 +884,24 @@ minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 
	int group = mi->max_prob_rate / MCS_GROUP_RATES;

	const struct mcs_group *g = &minstrel_mcs_groups[group];

	int rate = mi->max_prob_rate % MCS_GROUP_RATES;

	unsigned int duration;



	/* Disable A-MSDU if max_prob_rate is bad */

	if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))

		return 1;



	duration = g->duration[rate];

	duration <<= g->shift;



	/* If the rate is slower than single-stream MCS1, make A-MSDU limit small */

	if (g->duration[rate] > MCS_DURATION(1, 0, 52))

	if (duration > MCS_DURATION(1, 0, 52))

		return 500;



	/*

	 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual

	 * data packet size

	 */

	if (g->duration[rate] > MCS_DURATION(1, 0, 104))

	if (duration > MCS_DURATION(1, 0, 104))

		return 1600;



	/*
@@ -895,7 +909,7 @@ minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 
	 * rate success probability is less than 75%, limit A-MSDU to twice the usual

	 * data packet size

	 */

	if (g->duration[rate] > MCS_DURATION(1, 0, 260) ||

	if (duration > MCS_DURATION(1, 0, 260) ||

	    (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <

	     MINSTREL_FRAC(75, 100)))

		return 3200;
@@ -942,13 +956,6 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 
	rate_control_set_rates(mp->hw, mi->sta, rates);

}



static inline int

minstrel_get_duration(int index)

{

	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];

	return group->duration[index % MCS_GROUP_RATES];

}



static int

minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)

{

net/mac80211/rc80211_minstrel_ht.h

+4 −3
Original line number Diff line number Diff line
@@ -33,9 +33,10 @@ 
#define MCS_GROUP_RATES		10



struct mcs_group {

	u32 flags;

	unsigned int streams;

	unsigned int duration[MCS_GROUP_RATES];

	u16 flags;

	u8 streams;

	u8 shift;

	u16 duration[MCS_GROUP_RATES];

};



extern const struct mcs_group minstrel_mcs_groups[];

net/mac80211/rc80211_minstrel_ht_debugfs.c

+9 −2
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p) 
		static const int bitrates[4] = { 10, 20, 55, 110 };

		int idx = i * MCS_GROUP_RATES + j;

		unsigned int prob_ewmsd;

		unsigned int duration;



		if (!(mi->supported[i] & BIT(j)))

			continue;
@@ -95,7 +96,9 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p) 
		p += sprintf(p, "  %3u  ", idx);



		/* tx_time[rate(i)] in usec */

		tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);

		duration = mg->duration[j];

		duration <<= mg->shift;

		tx_time = DIV_ROUND_CLOSEST(duration, 1000);

		p += sprintf(p, "%6u  ", tx_time);



		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
@@ -204,6 +207,7 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p) 
		static const int bitrates[4] = { 10, 20, 55, 110 };

		int idx = i * MCS_GROUP_RATES + j;

		unsigned int prob_ewmsd;

		unsigned int duration;



		if (!(mi->supported[i] & BIT(j)))

			continue;
@@ -238,7 +242,10 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p) 
		}



		p += sprintf(p, "%u,", idx);

		tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);



		duration = mg->duration[j];

		duration <<= mg->shift;

		tx_time = DIV_ROUND_CLOSEST(duration, 1000);

		p += sprintf(p, "%u,", tx_time);



		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));