From: Javier Cardona <javier@xxxxxxxxxxx>
The mesh metric is computed every time it was requested by the path
selection framework. At that time only the last_tx_rate was taken into
account when computing the metric. This last frame may not reflect the
average data rate that was possible ver that peer link (it could be a
management frame, a rate control probe, or other outlier).
This patch maintains an average tx rate for each peer link which is used
in metric calculation.
Signed-off-by: Javier Cardona <javier@xxxxxxxxxxx>
Reviewed-by: Jason Abele <jason@xxxxxxxxxxx>
---
formerly sent as:
[PATCH v3 3/5] mac80211: Keep tx rate averages for mesh peers for better metric calculation.
net/mac80211/mesh_hwmp.c | 24 +++++++++++++++---------
net/mac80211/sta_info.c | 1 +
net/mac80211/sta_info.h | 1 +
3 files changed, 17 insertions(+), 9 deletions(-)
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 9b6da2d..22b327a 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -307,7 +307,9 @@ void ieee80211s_update_metric(struct ieee80211_local *local,
{
struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct rate_info rinfo;
int failed;
+ int rate;
if (!ieee80211_is_data(hdr->frame_control))
return;
@@ -318,36 +320,40 @@ void ieee80211s_update_metric(struct ieee80211_local *local,
sta->fail_avg = ((80 * sta->fail_avg + 5) / 100 + 20 * failed);
if (sta->fail_avg > 95)
mesh_plink_broken(sta);
+
+ sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
+ rate = cfg80211_calculate_bitrate(&rinfo);
+ if (WARN_ON(!rate))
+ return;
+
+ ewma_add(&sta->avg_rate, rate);
+ return;
}
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;
int s_unit = 1 << ARITH_SHIFT;
- int rate, err;
u32 tx_time, estimated_retx;
u64 result;
+ int rate;
+ int err = (sta->fail_avg << ARITH_SHIFT) / 100;
if (sta->fail_avg >= 100)
return MAX_METRIC;
- sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
- rate = cfg80211_calculate_bitrate(&rinfo);
- if (WARN_ON(!rate))
- return MAX_METRIC;
-
- err = (sta->fail_avg << ARITH_SHIFT) / 100;
+ /* If not enough values accumulated in rate average, assume 1 Mbps */
+ rate = max(ewma_read(&sta->avg_rate), 10UL);
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
*/
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
- result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
+ result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
return (u32)result;
}
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 77dcf2f..ddbec7b 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -256,6 +256,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
do_posix_clock_monotonic_gettime(&uptime);
sta->last_connected = uptime.tv_sec;
ewma_init(&sta->avg_signal, 1024, 8);
+ ewma_init(&sta->avg_rate, 1, 32);
if (sta_prepare_rate_control(local, sta, gfp)) {
kfree(sta);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 3bb24a1..0bf888e 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -330,6 +330,7 @@ struct sta_info {
unsigned long tx_retry_failed, tx_retry_count;
/* moving percentage of failed MSDUs */
unsigned int fail_avg;
+ struct ewma avg_rate;
/* Updated from TX path only, no locking requirements */
unsigned long tx_packets;
--
1.7.9.5
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