On Tue Jul 19, 2022 at 2:35 PM CEST, Baligh Gasmi wrote:
> Add a worker scheduled periodicaly to calculate the busy time average of
> the current channel.
>
> This will be used in the estimation for expected throughput.
>
> Signed-off-by: Baligh Gasmi <gasmibal@xxxxxxxxx>
> ---
> net/mac80211/ieee80211_i.h | 6 ++++
> net/mac80211/iface.c | 65 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 71 insertions(+)
>
> diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
> index 86ef0a46a68c..2cb388335ce8 100644
> --- a/net/mac80211/ieee80211_i.h
> +++ b/net/mac80211/ieee80211_i.h
> @@ -901,6 +901,7 @@ struct ieee80211_if_nan {
> struct idr function_inst_ids;
> };
>
> +DECLARE_EWMA(avg_busy, 8, 4)
> struct ieee80211_sub_if_data {
> struct list_head list;
>
> @@ -1024,6 +1025,11 @@ struct ieee80211_sub_if_data {
> } debugfs;
> #endif
>
> + struct delayed_work monitor_work;
> + u64 last_time;
> + u64 last_time_busy;
> + struct ewma_avg_busy avg_busy;
> +
> /* must be last, dynamically sized area in this! */
> struct ieee80211_vif vif;
> };
> diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
> index 15a73b7fdd75..e1b20964933c 100644
> --- a/net/mac80211/iface.c
> +++ b/net/mac80211/iface.c
> @@ -1972,6 +1972,64 @@ static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
> mutex_unlock(&local->iflist_mtx);
> }
>
> +#define DEFAULT_MONITOR_INTERVAL_MS 1000
> +
> +static void ieee80211_if_monitor_work(struct work_struct *work)
> +{
> + struct delayed_work *delayed_work = to_delayed_work(work);
> + struct ieee80211_sub_if_data *sdata > + container_of(delayed_work, struct ieee80211_sub_if_data,
> + monitor_work);
> + struct survey_info survey;
> + struct ieee80211_local *local = sdata->local;
> + struct ieee80211_chanctx_conf *chanctx_conf;
> + struct ieee80211_channel *channel = NULL;
> + int q = 0;
> + u64 interval = DEFAULT_MONITOR_INTERVAL_MS;
> +
> + rcu_read_lock();
> + chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
> + if (chanctx_conf)
> + channel = chanctx_conf->def.chan;
> + rcu_read_unlock();
> +
> + if (!channel)
> + goto end;
> +
> + if (!local->started)
> + goto end;
> +
> + do {
> + survey.filled = 0;
> + if (drv_get_survey(local, q++, &survey) != 0) {
> + survey.filled = 0;
> + break;
> + }
> + } while (channel != survey.channel);
> +
> + if (survey.filled & SURVEY_INFO_TIME) {
> + /* real interval */
> + interval = survey.time - sdata->last_time;
> + /* store last time */
> + sdata->last_time = survey.time;
> + }
> +
> + if (survey.filled & SURVEY_INFO_TIME_BUSY) {
> + /* busy */
> + u64 busy = survey.time_busy < sdata->last_time_busy ? 0 :
> + survey.time_busy - sdata->last_time_busy;
> + /* average percent busy time */
> + ewma_avg_busy_add(&sdata->avg_busy,
> + (busy * 100) / interval);
This could use a div_u64()
> + /* store last busy time */
> + sdata->last_time_busy = survey.time_busy;
> + }
> +
> +end:
> + schedule_delayed_work(&sdata->monitor_work,
> + msecs_to_jiffies(DEFAULT_MONITOR_INTERVAL_MS));
> +}
> +
> int ieee80211_if_add(struct ieee80211_local *local, const char *name,
> unsigned char name_assign_type,
> struct wireless_dev **new_wdev, enum nl80211_iftype type,
> @@ -2085,6 +2143,8 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
> ieee80211_dfs_cac_timer_work);
> INIT_DELAYED_WORK(&sdata->dec_tailroom_needed_wk,
> ieee80211_delayed_tailroom_dec);
> + INIT_DELAYED_WORK(&sdata->monitor_work,
> + ieee80211_if_monitor_work);
>
> for (i = 0; i < NUM_NL80211_BANDS; i++) {
> struct ieee80211_supported_band *sband;
> @@ -2156,6 +2216,9 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
> list_add_tail_rcu(&sdata->list, &local->interfaces);
> mutex_unlock(&local->iflist_mtx);
>
> + schedule_delayed_work(&sdata->monitor_work,
> + msecs_to_jiffies(DEFAULT_MONITOR_INTERVAL_MS));
> +
> if (new_wdev)
> *new_wdev = &sdata->wdev;
>
> @@ -2166,6 +2229,8 @@ void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
> {
> ASSERT_RTNL();
>
> + cancel_delayed_work_sync(&sdata->monitor_work);
> +
> mutex_lock(&sdata->local->iflist_mtx);
> list_del_rcu(&sdata->list);
> mutex_unlock(&sdata->local->iflist_mtx);
> --
> 2.37.1
