From f2af2df800d3648b1d68e02d5b8a5d77cfee8970 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 16 Mar 2019 18:06:32 +0100 Subject: [PATCH] mac80211: calculate hash for fq without holding fq->lock in itxq enqueue MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Reduces lock contention on enqueue/dequeue of iTXQ packets Signed-off-by: Felix Fietkau Acked-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg --- include/net/fq_impl.h | 18 ++++++++++-------- net/mac80211/tx.c | 15 ++++++++++----- 2 files changed, 20 insertions(+), 13 deletions(-) diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h index be7c0fab3478..2caa86660ab0 100644 --- a/include/net/fq_impl.h +++ b/include/net/fq_impl.h @@ -107,21 +107,23 @@ begin: return skb; } +static u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb) +{ + u32 hash = skb_get_hash_perturb(skb, fq->perturbation); + + return reciprocal_scale(hash, fq->flows_cnt); +} + static struct fq_flow *fq_flow_classify(struct fq *fq, - struct fq_tin *tin, + struct fq_tin *tin, u32 idx, struct sk_buff *skb, fq_flow_get_default_t get_default_func) { struct fq_flow *flow; - u32 hash; - u32 idx; lockdep_assert_held(&fq->lock); - hash = skb_get_hash_perturb(skb, fq->perturbation); - idx = reciprocal_scale(hash, fq->flows_cnt); flow = &fq->flows[idx]; - if (flow->tin && flow->tin != tin) { flow = get_default_func(fq, tin, idx, skb); tin->collisions++; @@ -153,7 +155,7 @@ static void fq_recalc_backlog(struct fq *fq, } static void fq_tin_enqueue(struct fq *fq, - struct fq_tin *tin, + struct fq_tin *tin, u32 idx, struct sk_buff *skb, fq_skb_free_t free_func, fq_flow_get_default_t get_default_func) @@ -163,7 +165,7 @@ static void fq_tin_enqueue(struct fq *fq, lockdep_assert_held(&fq->lock); - flow = fq_flow_classify(fq, tin, skb, get_default_func); + flow = fq_flow_classify(fq, tin, idx, skb, get_default_func); flow->tin = tin; flow->backlog += skb->len; diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 8a49a74c0a37..2c0fec888021 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1399,11 +1399,15 @@ static void ieee80211_txq_enqueue(struct ieee80211_local *local, { struct fq *fq = &local->fq; struct fq_tin *tin = &txqi->tin; + u32 flow_idx = fq_flow_idx(fq, skb); ieee80211_set_skb_enqueue_time(skb); - fq_tin_enqueue(fq, tin, skb, + + spin_lock_bh(&fq->lock); + fq_tin_enqueue(fq, tin, flow_idx, skb, fq_skb_free_func, fq_flow_get_default_func); + spin_unlock_bh(&fq->lock); } static bool fq_vlan_filter_func(struct fq *fq, struct fq_tin *tin, @@ -1590,7 +1594,6 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local, struct sta_info *sta, struct sk_buff *skb) { - struct fq *fq = &local->fq; struct ieee80211_vif *vif; struct txq_info *txqi; @@ -1608,9 +1611,7 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local, if (!txqi) return false; - spin_lock_bh(&fq->lock); ieee80211_txq_enqueue(local, txqi, skb); - spin_unlock_bh(&fq->lock); schedule_and_wake_txq(local, txqi); @@ -3221,6 +3222,7 @@ static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata, u8 max_subframes = sta->sta.max_amsdu_subframes; int max_frags = local->hw.max_tx_fragments; int max_amsdu_len = sta->sta.max_amsdu_len; + u32 flow_idx; __be16 len; void *data; bool ret = false; @@ -3249,6 +3251,8 @@ static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata, max_amsdu_len = min_t(int, max_amsdu_len, sta->sta.max_tid_amsdu_len[tid]); + flow_idx = fq_flow_idx(fq, skb); + spin_lock_bh(&fq->lock); /* TODO: Ideally aggregation should be done on dequeue to remain @@ -3256,7 +3260,8 @@ static bool ieee80211_amsdu_aggregate(struct ieee80211_sub_if_data *sdata, */ tin = &txqi->tin; - flow = fq_flow_classify(fq, tin, skb, fq_flow_get_default_func); + flow = fq_flow_classify(fq, tin, flow_idx, skb, + fq_flow_get_default_func); head = skb_peek_tail(&flow->queue); if (!head || skb_is_gso(head)) goto out; -- 2.30.2