mac80211: calculate hash for fq without holding fq->lock in itxq enqueue
Reduces lock contention on enqueue/dequeue of iTXQ packets
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
index be7c0fa..2caa866 100644
--- a/include/net/fq_impl.h
+++ b/include/net/fq_impl.h
@@ -107,21 +107,23 @@ static struct sk_buff *fq_tin_dequeue(struct fq *fq,
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 8a49a74..2c0fec8 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;