Commit 67fc0554 authored by Julan Hsu's avatar Julan Hsu Committed by Johannes Berg
Browse files

mac80211: mesh: use average bitrate for link metric calculation 



Use bitrate moving average to smooth out link metric and stablize path
selection.

Signed-off-by: default avatarJulan Hsu <julanhsu@google.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 540bbcb9

net/mac80211/cfg.c

+5 −0
Original line number Diff line number Diff line
@@ -1231,6 +1231,11 @@ static void sta_apply_mesh_params(struct ieee80211_local *local, 
			ieee80211_mps_sta_status_update(sta);

			changed |= ieee80211_mps_set_sta_local_pm(sta,

				      sdata->u.mesh.mshcfg.power_mode);



			ewma_mesh_tx_rate_avg_init(&sta->mesh->tx_rate_avg);

			/* init at low value */

			ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg, 10);



			break;

		case NL80211_PLINK_LISTEN:

		case NL80211_PLINK_BLOCKED:

net/mac80211/mesh_hwmp.c

+6 −3
Original line number Diff line number Diff line
@@ -300,6 +300,7 @@ void ieee80211s_update_metric(struct ieee80211_local *local, 
{

	struct ieee80211_tx_info *txinfo = st->info;

	int failed;

	struct rate_info rinfo;



	failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
@@ -310,12 +311,15 @@ void ieee80211s_update_metric(struct ieee80211_local *local, 
	if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >

			LINK_FAIL_THRESH)

		mesh_plink_broken(sta);



	sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);

	ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg,

				  cfg80211_calculate_bitrate(&rinfo));

}



static u32 airtime_link_metric_get(struct ieee80211_local *local,

				   struct sta_info *sta)

{

	struct rate_info rinfo;

	/* This should be adjusted for each device */

	int device_constant = 1 << ARITH_SHIFT;

	int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
@@ -339,8 +343,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local, 
		if (fail_avg > LINK_FAIL_THRESH)

			return MAX_METRIC;



		sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);

		rate = cfg80211_calculate_bitrate(&rinfo);

		rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg);

		if (WARN_ON(!rate))

			return MAX_METRIC;

net/mac80211/sta_info.h

+4 −0
Original line number Diff line number Diff line
@@ -353,6 +353,7 @@ struct ieee80211_fast_rx { 


/* we use only values in the range 0-100, so pick a large precision */

DECLARE_EWMA(mesh_fail_avg, 20, 8)

DECLARE_EWMA(mesh_tx_rate_avg, 8, 16)



/**

 * struct mesh_sta - mesh STA information
@@ -376,6 +377,7 @@ DECLARE_EWMA(mesh_fail_avg, 20, 8) 
 *	processed

 * @connected_to_gate: true if mesh STA has a path to a mesh gate

 * @fail_avg: moving percentage of failed MSDUs

 * @tx_rate_avg: moving average of tx bitrate

 */

struct mesh_sta {

	struct timer_list plink_timer;
@@ -404,6 +406,8 @@ struct mesh_sta { 


	/* moving percentage of failed MSDUs */

	struct ewma_mesh_fail_avg fail_avg;

	/* moving average of tx bitrate */

	struct ewma_mesh_tx_rate_avg tx_rate_avg;

};



DECLARE_EWMA(signal, 10, 8)