From 9c01c9f1f2a3ddbddbf3b233cc6bfa86f5a59af0 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Wed, 10 Apr 2019 14:32:39 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/net/sch_generic.h | 23 +++++++++++++--------- net/sched/sch_generic.c | 50 ++++++++++++++++------------------------------- 2 files changed, 31 insertions(+), 42 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 7ecb6127e980..ed56474cfe3b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -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); } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 81356ef38d1d..ddff2952be87 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -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; - - __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, -- 2.11.0