mac80211: minstrel: reduce size of struct minstrel_rate_stats

On minstrel_ht, the size of the per-sta struct is almost 18k, making it
an order-3 allocation.
A few fields inside the per-rate statistics are bigger than they need to
be. This patch reduces the size enough to cut down the per-sta struct to
about 13k (order-2 allocation).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index d51f6b1..7c86a00 100644 (file)
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -263,12 +263,12 @@ static inline unsigned int
 minstrel_get_retry_count(struct minstrel_rate *mr,
                         struct ieee80211_tx_info *info)
 {
-       unsigned int retry = mr->adjusted_retry_count;
+       u8 retry = mr->adjusted_retry_count;
 
        if (info->control.use_rts)
-               retry = max(2U, min(mr->stats.retry_count_rtscts, retry));
+               retry = max_t(u8, 2, min(mr->stats.retry_count_rtscts, retry));
        else if (info->control.use_cts_prot)
-               retry = max(2U, min(mr->retry_count_cts, retry));
+               retry = max_t(u8, 2, min(mr->retry_count_cts, retry));
        return retry;
 }
 

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 97eca86..410efe6 100644 (file)
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -33,8 +33,8 @@ minstrel_ewma(int old, int new, int weight)
 
 struct minstrel_rate_stats {
        /* current / last sampling period attempts/success counters */
-       unsigned int attempts, last_attempts;
-       unsigned int success, last_success;
+       u16 attempts, last_attempts;
+       u16 success, last_success;
 
        /* total attempts/success counters */
        u64 att_hist, succ_hist;
@@ -46,8 +46,8 @@ struct minstrel_rate_stats {
        unsigned int cur_prob, probability;
 
        /* maximum retry counts */
-       unsigned int retry_count;
-       unsigned int retry_count_rtscts;
+       u8 retry_count;
+       u8 retry_count_rtscts;
 
        u8 sample_skipped;
        bool retry_updated;
@@ -55,14 +55,15 @@ struct minstrel_rate_stats {
 
 struct minstrel_rate {
        int bitrate;
-       int rix;
+
+       s8 rix;
+       u8 retry_count_cts;
+       u8 adjusted_retry_count;
 
        unsigned int perfect_tx_time;
        unsigned int ack_time;
 
        int sample_limit;
-       unsigned int retry_count_cts;
-       unsigned int adjusted_retry_count;
 
        struct minstrel_rate_stats stats;
 };