From: Paolo Abeni <pabeni@redhat.com>
Date: Wed, 10 Apr 2019 14:32:39 +0200
Subject: net: sched: always do stats accounting according to TCQ_F_CPUSTATS
Patch-mainline: v5.2-rc1
Git-commit: 9c01c9f1f2a3ddbddbf3b233cc6bfa86f5a59af0
References: bsc#1183405
The core sched implementation checks independently for NOLOCK flag
to acquire/release the root spin lock and for qdisc_is_percpu_stats()
to account per CPU values in many places.
This change update the last few places checking the TCQ_F_NOLOCK to
do per CPU stats accounting according to qdisc_is_percpu_stats()
value.
The above allows to clean dev_requeue_skb() implementation a bit
and makes stats update always consistent with a single flag.
v1 -> v2:
- do not move qdisc_is_empty definition, fix build issue
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
include/net/sch_generic.h | 23 +++++++++++-------
net/sched/sch_generic.c | 50 +++++++++++++--------------------------
2 files changed, 31 insertions(+), 42 deletions(-)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -140,9 +140,14 @@ static inline bool qdisc_is_running(struct Qdisc *qdisc)
return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
}
+static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
+{
+ return q->flags & TCQ_F_CPUSTATS;
+}
+
static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
{
- if (qdisc->flags & TCQ_F_NOLOCK)
+ if (qdisc_is_percpu_stats(qdisc))
return qdisc->empty;
return !qdisc->q.qlen;
}
@@ -421,7 +426,7 @@ static inline u32 qdisc_qlen_sum(const struct Qdisc *q)
{
u32 qlen = q->qstats.qlen;
- if (q->flags & TCQ_F_NOLOCK)
+ if (qdisc_is_percpu_stats(q))
qlen += atomic_read(&q->q.atomic_qlen);
else
qlen += q->q.qlen;
@@ -722,11 +727,6 @@ static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
return sch->enqueue(skb, sch, to_free);
}
-static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
-{
- return q->flags & TCQ_F_CPUSTATS;
-}
-
static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
__u64 bytes, __u32 packets)
{
@@ -1018,8 +1018,13 @@ static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
if (skb) {
skb = __skb_dequeue(&sch->gso_skb);
- qdisc_qstats_backlog_dec(sch, skb);
- sch->q.qlen--;
+ if (qdisc_is_percpu_stats(sch)) {
+ qdisc_qstats_cpu_backlog_dec(sch, skb);
+ qdisc_qstats_atomic_qlen_dec(sch);
+ } else {
+ qdisc_qstats_backlog_dec(sch, skb);
+ sch->q.qlen--;
+ }
} else {
skb = sch->dequeue(sch);
}
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -119,52 +119,36 @@ static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q,
spin_unlock(lock);
}
-static inline int __dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
+static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
{
- while (skb) {
- struct sk_buff *next = skb->next;
-
- __skb_queue_tail(&q->gso_skb, skb);
- q->qstats.requeues++;
- qdisc_qstats_backlog_inc(q, skb);
- q->q.qlen++; /* it's still part of the queue */
+ spinlock_t *lock = NULL;
- skb = next;
+ if (q->flags & TCQ_F_NOLOCK) {
+ lock = qdisc_lock(q);
+ spin_lock(lock);
}
- __netif_schedule(q);
-
- return 0;
-}
-static inline int dev_requeue_skb_locked(struct sk_buff *skb, struct Qdisc *q)
-{
- spinlock_t *lock = qdisc_lock(q);
-
- spin_lock(lock);
while (skb) {
struct sk_buff *next = skb->next;
__skb_queue_tail(&q->gso_skb, skb);
- qdisc_qstats_cpu_requeues_inc(q);
- qdisc_qstats_cpu_backlog_inc(q, skb);
- qdisc_qstats_atomic_qlen_inc(q);
+ /* it's still part of the queue */
+ if (qdisc_is_percpu_stats(q)) {
+ qdisc_qstats_cpu_requeues_inc(q);
+ qdisc_qstats_cpu_backlog_inc(q, skb);
+ qdisc_qstats_atomic_qlen_inc(q);
+ } else {
+ q->qstats.requeues++;
+ qdisc_qstats_backlog_inc(q, skb);
+ q->q.qlen++;
+ }
skb = next;
}
- spin_unlock(lock);
-
+ if (lock)
+ spin_unlock(lock);
__netif_schedule(q);
-
- return 0;
-}
-
-static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
-{
- if (q->flags & TCQ_F_NOLOCK)
- return dev_requeue_skb_locked(skb, q);
- else
- return __dev_requeue_skb(skb, q);
}
static void try_bulk_dequeue_skb(struct Qdisc *q,