mac80211: add fq performace improvements

Improves performance under load

Signed-off-by: Felix Fietkau <nbd@nbd.name>

4 files changed, 554 insertions, 1 deletions

diff --git a/package/kernel/mac80211/patches/subsys/310-net-fq_impl-bulk-free-packets-from-a-flow-on-overmem.patch b/package/kernel/mac80211/patches/subsys/310-net-fq_impl-bulk-free-packets-from-a-flow-on-overmem.patch
new file mode 100644
index 0000000000..05a888006e
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/310-net-fq_impl-bulk-free-packets-from-a-flow-on-overmem.patch
@@ -0,0 +1,95 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Wed, 25 Nov 2020 18:03:46 +0100
+Subject: [PATCH] net/fq_impl: bulk-free packets from a flow on overmemory
+
+This is similar to what sch_fq_codel does. It also amortizes the worst
+case cost of a follow-up patch that changes the selection of the biggest
+flow for dropping packets
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/include/net/fq_impl.h
++++ b/include/net/fq_impl.h
+@@ -11,17 +11,25 @@
+ 
+ /* functions that are embedded into includer */
+ 
++
++static void
++__fq_adjust_removal(struct fq *fq, struct fq_flow *flow, unsigned int packets,
++		    unsigned int bytes, unsigned int truesize)
++{
++	struct fq_tin *tin = flow->tin;
++
++	tin->backlog_bytes -= bytes;
++	tin->backlog_packets -= packets;
++	flow->backlog -= bytes;
++	fq->backlog -= packets;
++	fq->memory_usage -= truesize;
++}
++
+ static void fq_adjust_removal(struct fq *fq,
+ 			      struct fq_flow *flow,
+ 			      struct sk_buff *skb)
+ {
+-	struct fq_tin *tin = flow->tin;
+-
+-	tin->backlog_bytes -= skb->len;
+-	tin->backlog_packets--;
+-	flow->backlog -= skb->len;
+-	fq->backlog--;
+-	fq->memory_usage -= skb->truesize;
++	__fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize);
+ }
+ 
+ static void fq_rejigger_backlog(struct fq *fq, struct fq_flow *flow)
+@@ -59,6 +67,34 @@ static struct sk_buff *fq_flow_dequeue(s
+ 	return skb;
+ }
+ 
++static int fq_flow_drop(struct fq *fq, struct fq_flow *flow,
++			fq_skb_free_t free_func)
++{
++	unsigned int packets = 0, bytes = 0, truesize = 0;
++	struct fq_tin *tin = flow->tin;
++	struct sk_buff *skb;
++	int pending;
++
++	lockdep_assert_held(&fq->lock);
++
++	pending = min_t(int, 32, skb_queue_len(&flow->queue) / 2);
++	do {
++		skb = __skb_dequeue(&flow->queue);
++		if (!skb)
++			break;
++
++		packets++;
++		bytes += skb->len;
++		truesize += skb->truesize;
++		free_func(fq, tin, flow, skb);
++	} while (packets < pending);
++
++	__fq_adjust_removal(fq, flow, packets, bytes, truesize);
++	fq_rejigger_backlog(fq, flow);
++
++	return packets;
++}
++
+ static struct sk_buff *fq_tin_dequeue(struct fq *fq,
+ 				      struct fq_tin *tin,
+ 				      fq_tin_dequeue_t dequeue_func)
+@@ -190,12 +226,9 @@ static void fq_tin_enqueue(struct fq *fq
+ 		if (!flow)
+ 			return;
+ 
+-		skb = fq_flow_dequeue(fq, flow);
+-		if (!skb)
++		if (!fq_flow_drop(fq, flow, free_func))
+ 			return;
+ 
+-		free_func(fq, flow->tin, flow, skb);
+-
+ 		flow->tin->overlimit++;
+ 		fq->overlimit++;
+ 		if (oom) {
diff --git a/package/kernel/mac80211/patches/subsys/311-net-fq_impl-drop-get_default_func-move-default-flow-.patch b/package/kernel/mac80211/patches/subsys/311-net-fq_impl-drop-get_default_func-move-default-flow-.patch
new file mode 100644
index 0000000000..de1f1bb7f5
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/311-net-fq_impl-drop-get_default_func-move-default-flow-.patch
@@ -0,0 +1,144 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Wed, 25 Nov 2020 18:09:10 +0100
+Subject: [PATCH] net/fq_impl: drop get_default_func, move default flow to
+ fq_tin
+
+Simplifies the code and prepares for a rework of scanning for flows on
+overmemory drop.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/include/net/fq.h
++++ b/include/net/fq.h
+@@ -47,6 +47,7 @@ struct fq_flow {
+ struct fq_tin {
+ 	struct list_head new_flows;
+ 	struct list_head old_flows;
++	struct fq_flow default_flow;
+ 	u32 backlog_bytes;
+ 	u32 backlog_packets;
+ 	u32 overlimit;
+--- a/include/net/fq_impl.h
++++ b/include/net/fq_impl.h
+@@ -151,8 +151,7 @@ static u32 fq_flow_idx(struct fq *fq, st
+ 
+ static struct fq_flow *fq_flow_classify(struct fq *fq,
+ 					struct fq_tin *tin, u32 idx,
+-					struct sk_buff *skb,
+-					fq_flow_get_default_t get_default_func)
++					struct sk_buff *skb)
+ {
+ 	struct fq_flow *flow;
+ 
+@@ -160,7 +159,7 @@ static struct fq_flow *fq_flow_classify(
+ 
+ 	flow = &fq->flows[idx];
+ 	if (flow->tin && flow->tin != tin) {
+-		flow = get_default_func(fq, tin, idx, skb);
++		flow = &tin->default_flow;
+ 		tin->collisions++;
+ 		fq->collisions++;
+ 	}
+@@ -192,15 +191,14 @@ static void fq_recalc_backlog(struct fq
+ static void fq_tin_enqueue(struct fq *fq,
+ 			   struct fq_tin *tin, u32 idx,
+ 			   struct sk_buff *skb,
+-			   fq_skb_free_t free_func,
+-			   fq_flow_get_default_t get_default_func)
++			   fq_skb_free_t free_func)
+ {
+ 	struct fq_flow *flow;
+ 	bool oom;
+ 
+ 	lockdep_assert_held(&fq->lock);
+ 
+-	flow = fq_flow_classify(fq, tin, idx, skb, get_default_func);
++	flow = fq_flow_classify(fq, tin, idx, skb);
+ 
+ 	flow->tin = tin;
+ 	flow->backlog += skb->len;
+@@ -331,6 +329,7 @@ static void fq_tin_init(struct fq_tin *t
+ {
+ 	INIT_LIST_HEAD(&tin->new_flows);
+ 	INIT_LIST_HEAD(&tin->old_flows);
++	fq_flow_init(&tin->default_flow);
+ }
+ 
+ static int fq_init(struct fq *fq, int flows_cnt)
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -855,7 +855,6 @@ enum txq_info_flags {
+  */
+ struct txq_info {
+ 	struct fq_tin tin;
+-	struct fq_flow def_flow;
+ 	struct codel_vars def_cvars;
+ 	struct codel_stats cstats;
+ 	struct sk_buff_head frags;
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -1322,7 +1322,7 @@ static struct sk_buff *codel_dequeue_fun
+ 	fq = &local->fq;
+ 
+ 	if (cvars == &txqi->def_cvars)
+-		flow = &txqi->def_flow;
++		flow = &txqi->tin.default_flow;
+ 	else
+ 		flow = &fq->flows[cvars - local->cvars];
+ 
+@@ -1365,7 +1365,7 @@ static struct sk_buff *fq_tin_dequeue_fu
+ 		cparams = &local->cparams;
+ 	}
+ 
+-	if (flow == &txqi->def_flow)
++	if (flow == &tin->default_flow)
+ 		cvars = &txqi->def_cvars;
+ 	else
+ 		cvars = &local->cvars[flow - fq->flows];
+@@ -1392,17 +1392,6 @@ static void fq_skb_free_func(struct fq *
+ 	ieee80211_free_txskb(&local->hw, skb);
+ }
+ 
+-static struct fq_flow *fq_flow_get_default_func(struct fq *fq,
+-						struct fq_tin *tin,
+-						int idx,
+-						struct sk_buff *skb)
+-{
+-	struct txq_info *txqi;
+-
+-	txqi = container_of(tin, struct txq_info, tin);
+-	return &txqi->def_flow;
+-}
+-
+ static void ieee80211_txq_enqueue(struct ieee80211_local *local,
+ 				  struct txq_info *txqi,
+ 				  struct sk_buff *skb)
+@@ -1415,8 +1404,7 @@ static void ieee80211_txq_enqueue(struct
+ 
+ 	spin_lock_bh(&fq->lock);
+ 	fq_tin_enqueue(fq, tin, flow_idx, skb,
+-		       fq_skb_free_func,
+-		       fq_flow_get_default_func);
++		       fq_skb_free_func);
+ 	spin_unlock_bh(&fq->lock);
+ }
+ 
+@@ -1459,7 +1447,6 @@ void ieee80211_txq_init(struct ieee80211
+ 			struct txq_info *txqi, int tid)
+ {
+ 	fq_tin_init(&txqi->tin);
+-	fq_flow_init(&txqi->def_flow);
+ 	codel_vars_init(&txqi->def_cvars);
+ 	codel_stats_init(&txqi->cstats);
+ 	__skb_queue_head_init(&txqi->frags);
+@@ -3310,8 +3297,7 @@ static bool ieee80211_amsdu_aggregate(st
+ 	 */
+ 
+ 	tin = &txqi->tin;
+-	flow = fq_flow_classify(fq, tin, flow_idx, skb,
+-				fq_flow_get_default_func);
++	flow = fq_flow_classify(fq, tin, flow_idx, skb);
+ 	head = skb_peek_tail(&flow->queue);
+ 	if (!head || skb_is_gso(head))
+ 		goto out;
diff --git a/package/kernel/mac80211/patches/subsys/312-net-fq_impl-do-not-maintain-a-backlog-sorted-list-of.patch b/package/kernel/mac80211/patches/subsys/312-net-fq_impl-do-not-maintain-a-backlog-sorted-list-of.patch
new file mode 100644
index 0000000000..0e923991db
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/312-net-fq_impl-do-not-maintain-a-backlog-sorted-list-of.patch
@@ -0,0 +1,314 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Wed, 25 Nov 2020 18:10:34 +0100
+Subject: [PATCH] net/fq_impl: do not maintain a backlog-sorted list of
+ flows
+
+A sorted flow list is only needed to drop packets in the biggest flow when
+hitting the overmemory condition.
+By scanning flows only when needed, we can avoid paying the cost of
+maintaining the list under normal conditions
+In order to avoid scanning lots of empty flows and touching too many cold
+cache lines, a bitmap of flows with backlog is maintained
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/include/net/fq.h
++++ b/include/net/fq.h
+@@ -19,8 +19,6 @@ struct fq_tin;
+  * @flowchain: can be linked to fq_tin's new_flows or old_flows. Used for DRR++
+  *	(deficit round robin) based round robin queuing similar to the one
+  *	found in net/sched/sch_fq_codel.c
+- * @backlogchain: can be linked to other fq_flow and fq. Used to keep track of
+- *	fat flows and efficient head-dropping if packet limit is reached
+  * @queue: sk_buff queue to hold packets
+  * @backlog: number of bytes pending in the queue. The number of packets can be
+  *	found in @queue.qlen
+@@ -29,7 +27,6 @@ struct fq_tin;
+ struct fq_flow {
+ 	struct fq_tin *tin;
+ 	struct list_head flowchain;
+-	struct list_head backlogchain;
+ 	struct sk_buff_head queue;
+ 	u32 backlog;
+ 	int deficit;
+@@ -47,6 +44,7 @@ struct fq_flow {
+ struct fq_tin {
+ 	struct list_head new_flows;
+ 	struct list_head old_flows;
++	struct list_head tin_list;
+ 	struct fq_flow default_flow;
+ 	u32 backlog_bytes;
+ 	u32 backlog_packets;
+@@ -60,14 +58,14 @@ struct fq_tin {
+ /**
+  * struct fq - main container for fair queuing purposes
+  *
+- * @backlogs: linked to fq_flows. Used to maintain fat flows for efficient
+- *	head-dropping when @backlog reaches @limit
+  * @limit: max number of packets that can be queued across all flows
+  * @backlog: number of packets queued across all flows
+  */
+ struct fq {
+ 	struct fq_flow *flows;
+-	struct list_head backlogs;
++	unsigned long *flows_bitmap;
++
++	struct list_head tin_backlog;
+ 	spinlock_t lock;
+ 	u32 flows_cnt;
+ 	u32 limit;
+--- a/include/net/fq_impl.h
++++ b/include/net/fq_impl.h
+@@ -17,12 +17,24 @@ __fq_adjust_removal(struct fq *fq, struc
+ 		    unsigned int bytes, unsigned int truesize)
+ {
+ 	struct fq_tin *tin = flow->tin;
++	int idx;
+ 
+ 	tin->backlog_bytes -= bytes;
+ 	tin->backlog_packets -= packets;
+ 	flow->backlog -= bytes;
+ 	fq->backlog -= packets;
+ 	fq->memory_usage -= truesize;
++
++	if (flow->backlog)
++		return;
++
++	if (flow == &tin->default_flow) {
++		list_del_init(&tin->tin_list);
++		return;
++	}
++
++	idx = flow - fq->flows;
++	__clear_bit(idx, fq->flows_bitmap);
+ }
+ 
+ static void fq_adjust_removal(struct fq *fq,
+@@ -32,24 +44,6 @@ static void fq_adjust_removal(struct fq
+ 	__fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize);
+ }
+ 
+-static void fq_rejigger_backlog(struct fq *fq, struct fq_flow *flow)
+-{
+-	struct fq_flow *i;
+-
+-	if (flow->backlog == 0) {
+-		list_del_init(&flow->backlogchain);
+-	} else {
+-		i = flow;
+-
+-		list_for_each_entry_continue(i, &fq->backlogs, backlogchain)
+-			if (i->backlog < flow->backlog)
+-				break;
+-
+-		list_move_tail(&flow->backlogchain,
+-			       &i->backlogchain);
+-	}
+-}
+-
+ static struct sk_buff *fq_flow_dequeue(struct fq *fq,
+ 				       struct fq_flow *flow)
+ {
+@@ -62,7 +56,6 @@ static struct sk_buff *fq_flow_dequeue(s
+ 		return NULL;
+ 
+ 	fq_adjust_removal(fq, flow, skb);
+-	fq_rejigger_backlog(fq, flow);
+ 
+ 	return skb;
+ }
+@@ -90,7 +83,6 @@ static int fq_flow_drop(struct fq *fq, s
+ 	} while (packets < pending);
+ 
+ 	__fq_adjust_removal(fq, flow, packets, bytes, truesize);
+-	fq_rejigger_backlog(fq, flow);
+ 
+ 	return packets;
+ }
+@@ -170,22 +162,36 @@ static struct fq_flow *fq_flow_classify(
+ 	return flow;
+ }
+ 
+-static void fq_recalc_backlog(struct fq *fq,
+-			      struct fq_tin *tin,
+-			      struct fq_flow *flow)
++static struct fq_flow *fq_find_fattest_flow(struct fq *fq)
+ {
+-	struct fq_flow *i;
++	struct fq_tin *tin;
++	struct fq_flow *flow = NULL;
++	u32 len = 0;
++	int i;
+ 
+-	if (list_empty(&flow->backlogchain))
+-		list_add_tail(&flow->backlogchain, &fq->backlogs);
++	for_each_set_bit(i, fq->flows_bitmap, fq->flows_cnt) {
++		struct fq_flow *cur = &fq->flows[i];
++		unsigned int cur_len;
+ 
+-	i = flow;
+-	list_for_each_entry_continue_reverse(i, &fq->backlogs,
+-					     backlogchain)
+-		if (i->backlog > flow->backlog)
+-			break;
++		cur_len = cur->backlog;
++		if (cur_len <= len)
++			continue;
+ 
+-	list_move(&flow->backlogchain, &i->backlogchain);
++		flow = cur;
++		len = cur_len;
++	}
++
++	list_for_each_entry(tin, &fq->tin_backlog, tin_list) {
++		unsigned int cur_len = tin->default_flow.backlog;
++
++		if (cur_len <= len)
++			continue;
++
++		flow = &tin->default_flow;
++		len = cur_len;
++	}
++
++	return flow;
+ }
+ 
+ static void fq_tin_enqueue(struct fq *fq,
+@@ -200,6 +206,13 @@ static void fq_tin_enqueue(struct fq *fq
+ 
+ 	flow = fq_flow_classify(fq, tin, idx, skb);
+ 
++	if (!flow->backlog) {
++		if (flow != &tin->default_flow)
++			__set_bit(idx, fq->flows_bitmap);
++		else if (list_empty(&tin->tin_list))
++			list_add(&tin->tin_list, &fq->tin_backlog);
++	}
++
+ 	flow->tin = tin;
+ 	flow->backlog += skb->len;
+ 	tin->backlog_bytes += skb->len;
+@@ -207,8 +220,6 @@ static void fq_tin_enqueue(struct fq *fq
+ 	fq->memory_usage += skb->truesize;
+ 	fq->backlog++;
+ 
+-	fq_recalc_backlog(fq, tin, flow);
+-
+ 	if (list_empty(&flow->flowchain)) {
+ 		flow->deficit = fq->quantum;
+ 		list_add_tail(&flow->flowchain,
+@@ -218,9 +229,7 @@ static void fq_tin_enqueue(struct fq *fq
+ 	__skb_queue_tail(&flow->queue, skb);
+ 	oom = (fq->memory_usage > fq->memory_limit);
+ 	while (fq->backlog > fq->limit || oom) {
+-		flow = list_first_entry_or_null(&fq->backlogs,
+-						struct fq_flow,
+-						backlogchain);
++		flow = fq_find_fattest_flow(fq);
+ 		if (!flow)
+ 			return;
+ 
+@@ -255,8 +264,6 @@ static void fq_flow_filter(struct fq *fq
+ 		fq_adjust_removal(fq, flow, skb);
+ 		free_func(fq, tin, flow, skb);
+ 	}
+-
+-	fq_rejigger_backlog(fq, flow);
+ }
+ 
+ static void fq_tin_filter(struct fq *fq,
+@@ -279,16 +286,18 @@ static void fq_flow_reset(struct fq *fq,
+ 			  struct fq_flow *flow,
+ 			  fq_skb_free_t free_func)
+ {
++	struct fq_tin *tin = flow->tin;
+ 	struct sk_buff *skb;
+ 
+ 	while ((skb = fq_flow_dequeue(fq, flow)))
+-		free_func(fq, flow->tin, flow, skb);
++		free_func(fq, tin, flow, skb);
+ 
+-	if (!list_empty(&flow->flowchain))
++	if (!list_empty(&flow->flowchain)) {
+ 		list_del_init(&flow->flowchain);
+-
+-	if (!list_empty(&flow->backlogchain))
+-		list_del_init(&flow->backlogchain);
++		if (list_empty(&tin->new_flows) &&
++		    list_empty(&tin->old_flows))
++			list_del_init(&tin->tin_list);
++	}
+ 
+ 	flow->tin = NULL;
+ 
+@@ -314,6 +323,7 @@ static void fq_tin_reset(struct fq *fq,
+ 		fq_flow_reset(fq, flow, free_func);
+ 	}
+ 
++	WARN_ON_ONCE(!list_empty(&tin->tin_list));
+ 	WARN_ON_ONCE(tin->backlog_bytes);
+ 	WARN_ON_ONCE(tin->backlog_packets);
+ }
+@@ -321,7 +331,6 @@ static void fq_tin_reset(struct fq *fq,
+ static void fq_flow_init(struct fq_flow *flow)
+ {
+ 	INIT_LIST_HEAD(&flow->flowchain);
+-	INIT_LIST_HEAD(&flow->backlogchain);
+ 	__skb_queue_head_init(&flow->queue);
+ }
+ 
+@@ -329,6 +338,7 @@ static void fq_tin_init(struct fq_tin *t
+ {
+ 	INIT_LIST_HEAD(&tin->new_flows);
+ 	INIT_LIST_HEAD(&tin->old_flows);
++	INIT_LIST_HEAD(&tin->tin_list);
+ 	fq_flow_init(&tin->default_flow);
+ }
+ 
+@@ -337,8 +347,8 @@ static int fq_init(struct fq *fq, int fl
+ 	int i;
+ 
+ 	memset(fq, 0, sizeof(fq[0]));
+-	INIT_LIST_HEAD(&fq->backlogs);
+ 	spin_lock_init(&fq->lock);
++	INIT_LIST_HEAD(&fq->tin_backlog);
+ 	fq->flows_cnt = max_t(u32, flows_cnt, 1);
+ 	fq->quantum = 300;
+ 	fq->limit = 8192;
+@@ -348,6 +358,14 @@ static int fq_init(struct fq *fq, int fl
+ 	if (!fq->flows)
+ 		return -ENOMEM;
+ 
++	fq->flows_bitmap = kcalloc(BITS_TO_LONGS(fq->flows_cnt), sizeof(long),
++				   GFP_KERNEL);
++	if (!fq->flows_bitmap) {
++		kvfree(fq->flows);
++		fq->flows = NULL;
++		return -ENOMEM;
++	}
++
+ 	for (i = 0; i < fq->flows_cnt; i++)
+ 		fq_flow_init(&fq->flows[i]);
+ 
+@@ -364,6 +382,9 @@ static void fq_reset(struct fq *fq,
+ 
+ 	kvfree(fq->flows);
+ 	fq->flows = NULL;
++
++	kfree(fq->flows_bitmap);
++	fq->flows_bitmap = NULL;
+ }
+ 
+ #endif
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -3364,8 +3364,6 @@ out_recalc:
+ 	if (head->len != orig_len) {
+ 		flow->backlog += head->len - orig_len;
+ 		tin->backlog_bytes += head->len - orig_len;
+-
+-		fq_recalc_backlog(fq, tin, flow);
+ 	}
+ out:
+ 	spin_unlock_bh(&fq->lock);
diff --git a/package/kernel/mac80211/patches/subsys/500-mac80211_configure_antenna_gain.patch b/package/kernel/mac80211/patches/subsys/500-mac80211_configure_antenna_gain.patch
index d76fc88238..cd2a3b424f 100644
--- a/package/kernel/mac80211/patches/subsys/500-mac80211_configure_antenna_gain.patch
+++ b/package/kernel/mac80211/patches/subsys/500-mac80211_configure_antenna_gain.patch
@@ -87,7 +87,7 @@
  	CFG80211_TESTMODE_CMD(ieee80211_testmode_cmd)
 --- a/net/mac80211/ieee80211_i.h
 +++ b/net/mac80211/ieee80211_i.h
-@@ -1401,6 +1401,7 @@ struct ieee80211_local {
+@@ -1400,6 +1400,7 @@ struct ieee80211_local {
  	int dynamic_ps_forced_timeout;
  
  	int user_power_level; /* in dBm, for all interfaces */