On 2014-08-22 16:05, Thomas Huehn wrote:
> 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-loops.
>
> 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 D the 4th fastest.
>
> Signed-off-by: Thomas Huehn <thomas@xxxxxxxxxxxxxxxxxxxxxxx>
> Tested-by: Stefan Venz <ikstream86@xxxxxxxxx>
> ---
> net/mac80211/rc80211_minstrel_ht.c | 215 ++++++++++++++++-------------
> net/mac80211/rc80211_minstrel_ht.h | 17 +--
> net/mac80211/rc80211_minstrel_ht_debugfs.c | 8 +-
> 3 files changed, 128 insertions(+), 112 deletions(-)
>
> diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
> index 85c1e74..7f03c01 100644
> --- a/net/mac80211/rc80211_minstrel_ht.c
> +++ b/net/mac80211/rc80211_minstrel_ht.c
> @@ -228,8 +227,47 @@ minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
> nsecs += minstrel_mcs_groups[group].duration[rate];
>
> /* prob is scaled - see MINSTREL_FRAC above */
> - tp = 1000000 * ((prob * 1000) / nsecs);
> - mr->cur_tp = MINSTREL_TRUNC(tp);
> + mr->cur_tp = 1000000 * ((prob * 1000) / nsecs);
> +}
> +
> +/*
> + * Find & sort topmost throughput rates
> + *
> + * If multiple rates provide equal throughput the sorting is based on their
> + * current success probability. Higher success probability is preferred among
> + * MCS groups, CCK rates do not provide aggregation and are therefore at last.
> + */
> +static inline void
You should drop the 'inline'
> +minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, unsigned int index,
> + unsigned int *tp_list)
> +{
> + int j = MAX_THR_RATES;
> + unsigned int cur_group, cur_idx, cur_thr, cur_prob;
> + unsigned int tmp_group, tmp_idx;
> +
> + cur_group = index / MCS_GROUP_RATES;
> + cur_idx = index % MCS_GROUP_RATES;
> + cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
> + cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
> + tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
> + tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
> +
> +
> + while (j > 0 && (cur_thr > mi->groups[tmp_group].rates[tmp_idx].cur_tp ||
> + (cur_thr == mi->groups[tmp_group].rates[tmp_idx].cur_tp &&
> + cur_prob > mi->groups[tmp_group].rates[tmp_idx].probability &&
> + cur_group != MINSTREL_CCK_GROUP))) {
Missing one whitespace in indentation in the above two lines
> + j--;
> + tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
> + tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
One tab too many.
I think it would probably make the code more readable if you just do
while (j > 0) { ... } and move the other checks inside the block.
> + }
> +
> + if (j < MAX_THR_RATES - 1) {
> + memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
> + (MAX_THR_RATES - (j + 1))));
> + }
> + if (j < MAX_THR_RATES)
> + tp_list[j] = index;
> }
>
> /*
> @@ -274,24 +312,17 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
>
> mi->sample_count++;
>
> + /* (re)Initialize group rate indexes */
> + for(j = 0; j < MAX_THR_RATES; j++){
> + tmp_group_tp_rate[j] = group;
> + }
You can drop the {} here.
> @@ -300,82 +331,72 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
> [...]
>
> + /* try to sample all available rates during each interval */
> + mi->sample_count *= 8;
> +
> #ifdef CONFIG_MAC80211_DEBUGFS
> /* use fixed index if set */
> if (mp->fixed_rate_idx != -1) {
> - mi->max_tp_rate = mp->fixed_rate_idx;
> - mi->max_tp_rate2 = mp->fixed_rate_idx;
> + for (i = 0; i < 4; i++) {
> + mi->max_tp_rate[i] = mp->fixed_rate_idx;
> + }
You can drop the {}
> mi->max_prob_rate = mp->fixed_rate_idx;
> }
> #endif
>
> + /* Reset update timer */
> mi->stats_update = jiffies;
> }
>
> @@ -735,8 +756,8 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
> * if the link is working perfectly.
> */
> sample_dur = minstrel_get_duration(sample_idx);
> - if (sample_dur >= minstrel_get_duration(mi->max_tp_rate2) &&
> - (mi->max_prob_streams <
> + if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
> + (minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES].streams <
Changing the code from checking max_prob_rate streams to max_tp_rate
streams should be done in a separate change and properly explained.
> minstrel_mcs_groups[sample_group].streams ||
> sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
> if (mr->sample_skipped < 20)
- Felix
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