From a8d418d9ac25f85a9caf652a4b2d07ec790474ab Mon Sep 17 00:00:00 2001 From: Julan Hsu Date: Tue, 15 Jan 2019 15:33:03 -0800 Subject: [PATCH] mac80211: mesh: only switch path when new metric is at least 10% better This helps to reduce frequent path switches when multiple path candidates have the same or very similar path metrics. Signed-off-by: Julan Hsu Signed-off-by: Johannes Berg --- net/mac80211/mesh_hwmp.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index f50409635a16..e00284afdda5 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -447,7 +447,10 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, (mpath->flags & MESH_PATH_SN_VALID)) { if (SN_GT(mpath->sn, orig_sn) || (mpath->sn == orig_sn && - new_metric >= mpath->metric)) { + (rcu_access_pointer(mpath->next_hop) != + sta ? + mult_frac(new_metric, 10, 9) : + new_metric) >= mpath->metric)) { process = false; fresh_info = false; } @@ -515,8 +518,10 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, if (mpath) { spin_lock_bh(&mpath->state_lock); if ((mpath->flags & MESH_PATH_FIXED) || - ((mpath->flags & MESH_PATH_ACTIVE) && - (last_hop_metric > mpath->metric))) + ((mpath->flags & MESH_PATH_ACTIVE) && + ((rcu_access_pointer(mpath->next_hop) != sta ? + mult_frac(last_hop_metric, 10, 9) : + last_hop_metric) > mpath->metric))) fresh_info = false; } else { mpath = mesh_path_add(sdata, ta); -- 2.11.0