Commit f56940da authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by David S. Miller
Browse files

net: sched: Use _bstats_update/set() instead of raw writes 



The Qdisc::running sequence counter, used to protect Qdisc::bstats reads
from parallel writes, is in the process of being removed. Qdisc::bstats
read/writes will synchronize using an internal u64_stats sync point
instead.

Modify all bstats writes to use _bstats_update(). This ensures that
the internal u64_stats sync point is always acquired and released as
appropriate.

Signed-off-by: default avatarAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 67c9e627

net/core/gen_stats.c

+5 −4
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ EXPORT_SYMBOL(gnet_stats_basic_packed_init); 
static void gnet_stats_add_basic_cpu(struct gnet_stats_basic_packed *bstats,

				     struct gnet_stats_basic_cpu __percpu *cpu)

{

	u64 t_bytes = 0, t_packets = 0;

	int i;



	for_each_possible_cpu(i) {
@@ -139,9 +140,10 @@ static void gnet_stats_add_basic_cpu(struct gnet_stats_basic_packed *bstats, 
			packets = bcpu->bstats.packets;

		} while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));



		bstats->bytes += bytes;

		bstats->packets += packets;

		t_bytes += bytes;

		t_packets += packets;

	}

	_bstats_update(bstats, t_bytes, t_packets);

}



void gnet_stats_add_basic(const seqcount_t *running,
@@ -164,8 +166,7 @@ void gnet_stats_add_basic(const seqcount_t *running, 
		packets = b->packets;

	} while (running && read_seqcount_retry(running, seq));



	bstats->bytes += bytes;

	bstats->packets += packets;

	_bstats_update(bstats, bytes, packets);

}

EXPORT_SYMBOL(gnet_stats_add_basic);

net/sched/sch_cbq.c

+1 −2
Original line number Diff line number Diff line
@@ -565,8 +565,7 @@ cbq_update(struct cbq_sched_data *q) 
		long avgidle = cl->avgidle;

		long idle;



		cl->bstats.packets++;

		cl->bstats.bytes += len;

		_bstats_update(&cl->bstats, len, 1);



		/*

		 * (now - last) is total time between packet right edges.

net/sched/sch_gred.c

+4 −3
Original line number Diff line number Diff line
@@ -353,6 +353,7 @@ static int gred_offload_dump_stats(struct Qdisc *sch) 
{

	struct gred_sched *table = qdisc_priv(sch);

	struct tc_gred_qopt_offload *hw_stats;

	u64 bytes = 0, packets = 0;

	unsigned int i;

	int ret;
@@ -381,15 +382,15 @@ static int gred_offload_dump_stats(struct Qdisc *sch) 
		table->tab[i]->bytesin += hw_stats->stats.bstats[i].bytes;

		table->tab[i]->backlog += hw_stats->stats.qstats[i].backlog;



		_bstats_update(&sch->bstats,

			       hw_stats->stats.bstats[i].bytes,

			       hw_stats->stats.bstats[i].packets);

		bytes += hw_stats->stats.bstats[i].bytes;

		packets += hw_stats->stats.bstats[i].packets;

		sch->qstats.qlen += hw_stats->stats.qstats[i].qlen;

		sch->qstats.backlog += hw_stats->stats.qstats[i].backlog;

		sch->qstats.drops += hw_stats->stats.qstats[i].drops;

		sch->qstats.requeues += hw_stats->stats.qstats[i].requeues;

		sch->qstats.overlimits += hw_stats->stats.qstats[i].overlimits;

	}

	_bstats_update(&sch->bstats, bytes, packets);



	kfree(hw_stats);

	return ret;

net/sched/sch_htb.c

+15 −10
Original line number Diff line number Diff line
@@ -1308,6 +1308,7 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg, 
static void htb_offload_aggregate_stats(struct htb_sched *q,

					struct htb_class *cl)

{

	u64 bytes = 0, packets = 0;

	struct htb_class *c;

	unsigned int i;
@@ -1323,14 +1324,15 @@ static void htb_offload_aggregate_stats(struct htb_sched *q, 
			if (p != cl)

				continue;



			cl->bstats.bytes += c->bstats_bias.bytes;

			cl->bstats.packets += c->bstats_bias.packets;

			bytes += c->bstats_bias.bytes;

			packets += c->bstats_bias.packets;

			if (c->level == 0) {

				cl->bstats.bytes += c->leaf.q->bstats.bytes;

				cl->bstats.packets += c->leaf.q->bstats.packets;

				bytes += c->leaf.q->bstats.bytes;

				packets += c->leaf.q->bstats.packets;

			}

		}

	}

	_bstats_update(&cl->bstats, bytes, packets);

}



static int
@@ -1358,8 +1360,9 @@ htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d) 
				cl->bstats = cl->leaf.q->bstats;

			else

				gnet_stats_basic_packed_init(&cl->bstats);

			cl->bstats.bytes += cl->bstats_bias.bytes;

			cl->bstats.packets += cl->bstats_bias.packets;

			_bstats_update(&cl->bstats,

				       cl->bstats_bias.bytes,

				       cl->bstats_bias.packets);

		} else {

			htb_offload_aggregate_stats(q, cl);

		}
@@ -1578,8 +1581,9 @@ static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl, 
		WARN_ON(old != q);



	if (cl->parent) {

		cl->parent->bstats_bias.bytes += q->bstats.bytes;

		cl->parent->bstats_bias.packets += q->bstats.packets;

		_bstats_update(&cl->parent->bstats_bias,

			       q->bstats.bytes,

			       q->bstats.packets);

	}



	offload_opt = (struct tc_htb_qopt_offload) {
@@ -1925,8 +1929,9 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, 
				htb_graft_helper(dev_queue, old_q);

				goto err_kill_estimator;

			}

			parent->bstats_bias.bytes += old_q->bstats.bytes;

			parent->bstats_bias.packets += old_q->bstats.packets;

			_bstats_update(&parent->bstats_bias,

				       old_q->bstats.bytes,

				       old_q->bstats.packets);

			qdisc_put(old_q);

		}

		new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,

net/sched/sch_qfq.c

+1 −2
Original line number Diff line number Diff line
@@ -1235,8 +1235,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 
		return err;

	}



	cl->bstats.bytes += len;

	cl->bstats.packets += gso_segs;

	_bstats_update(&cl->bstats, len, gso_segs);

	sch->qstats.backlog += len;

	++sch->q.qlen;