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>
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index 5db0f42..8065da2 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -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));