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net: sched: always do stats accounting according to TCQ_F_CPUSTATS 

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>
This commit is contained in:
Paolo Abeni 2019-04-10 14:32:39 +02:00 committed by David S. Miller
parent 1f5e6fdd6a
commit 9c01c9f1f2
2 changed files with 31 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
include/net/sch_generic.h
View File

@ -146,9 +146,14 @@ 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;
}
@ -490,7 +495,7 @@ 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;
@ -817,11 +822,6 @@ 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)
{
@ -1113,8 +1113,13 @@ 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);
}

50
net/sched/sch_generic.c
View File

@ -118,52 +118,36 @@ 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;
spinlock_t *lock = NULL;
__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 */
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,