2017-02-15 20:46:58

by Rajkumar Manoharan

Subject: [PATCH v2] mac80211: fix mesh fail_avg check

Mesh failure average never be more than 100. Only in case of
fixed path, average will be more than threshold limit (95%).
With recent EWMA changes it may go upto 99 as it is scaled to
100. It make sense to return maximum metric when average is
greater than threshold limit.

Signed-off-by: Rajkumar Manoharan <[email protected]>
---
v2: define MACRO for threshold

net/mac80211/mesh_hwmp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index d07ee3ca07ee..4005edd71fe8 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -16,6 +16,7 @@
#define TEST_FRAME_LEN 8192
#define MAX_METRIC 0xffffffff
#define ARITH_SHIFT 8
+#define LINK_FAIL_THRESH 95

#define MAX_PREQ_QUEUE_LEN 64

@@ -311,7 +312,8 @@ void ieee80211s_update_metric(struct ieee80211_local *local,
* feed failure as 100 and success as 0
*/
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
- if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > 95)
+ if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
+ LINK_FAIL_THRESH)
mesh_plink_broken(sta);
}

@@ -339,7 +341,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
if (rate) {
err = 0;
} else {
- if (fail_avg >= 100)
+ if (fail_avg > LINK_FAIL_THRESH)
return MAX_METRIC;

sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
--
1.9.1

2017-02-27 13:56:57

by Johannes Berg

Subject: Re: [PATCH v2] mac80211: fix mesh fail_avg check

On Wed, 2017-02-15 at 12:46 -0800, Rajkumar Manoharan wrote:
> Mesh failure average never be more than 100. Only in case of
> fixed path, average will be more than threshold limit (95%).
> With recent EWMA changes it may go upto 99 as it is scaled to
> 100. It make sense to return maximum metric when average is
> greater than threshold limit.

Applied, thanks.

johannes