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authorPaolo Abeni <pabeni@redhat.com>2019-04-10 15:32:41 +0300
committerDavid S. Miller <davem@davemloft.net>2019-04-10 22:20:46 +0300
commit73eb628ddfd3884d1e58a8022de2e78de7807fc6 (patch)
treef9963afb03df6761396729cfad94621e7d3d5ab0 /include
parent8a53e616de294873fec1a75ddb77ecb3d225cee0 (diff)
downloadlinux-73eb628ddfd3884d1e58a8022de2e78de7807fc6.tar.xz
Revert: "net: sched: put back q.qlen into a single location"
This revert commit 46b1c18f9deb ("net: sched: put back q.qlen into a single location"). After the previous patch, when a NOLOCK qdisc is enslaved to a locking qdisc it switches to global stats accounting. As a consequence, when a classful qdisc accesses directly a child qdisc's qlen, such qdisc is not doing per CPU accounting and qlen value is consistent. In the control path nobody uses directly qlen since commit e5f0e8f8e45 ("net: sched: introduce and use qdisc tree flush/purge helpers"), so we can remove the contented atomic ops from the datapath. v1 -> v2: - complete the qdisc_qstats_atomic_qlen_dec() -> qdisc_qstats_cpu_qlen_dec() replacement, fix build issue - more descriptive commit message Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/net/sch_generic.h37
1 files changed, 21 insertions, 16 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index f069011524ba..e8f85cd2afce 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -52,10 +52,7 @@ struct qdisc_size_table {
struct qdisc_skb_head {
struct sk_buff *head;
struct sk_buff *tail;
- union {
- u32 qlen;
- atomic_t atomic_qlen;
- };
+ __u32 qlen;
spinlock_t lock;
};
@@ -486,19 +483,27 @@ static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
BUILD_BUG_ON(sizeof(qcb->data) < sz);
}
+static inline int qdisc_qlen_cpu(const struct Qdisc *q)
+{
+ return this_cpu_ptr(q->cpu_qstats)->qlen;
+}
+
static inline int qdisc_qlen(const struct Qdisc *q)
{
return q->q.qlen;
}
-static inline u32 qdisc_qlen_sum(const struct Qdisc *q)
+static inline int qdisc_qlen_sum(const struct Qdisc *q)
{
- u32 qlen = q->qstats.qlen;
+ __u32 qlen = q->qstats.qlen;
+ int i;
- if (qdisc_is_percpu_stats(q))
- qlen += atomic_read(&q->q.atomic_qlen);
- else
+ if (qdisc_is_percpu_stats(q)) {
+ for_each_possible_cpu(i)
+ qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
+ } else {
qlen += q->q.qlen;
+ }
return qlen;
}
@@ -889,14 +894,14 @@ static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
}
-static inline void qdisc_qstats_atomic_qlen_inc(struct Qdisc *sch)
+static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
{
- atomic_inc(&sch->q.atomic_qlen);
+ this_cpu_inc(sch->cpu_qstats->qlen);
}
-static inline void qdisc_qstats_atomic_qlen_dec(struct Qdisc *sch)
+static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
{
- atomic_dec(&sch->q.atomic_qlen);
+ this_cpu_dec(sch->cpu_qstats->qlen);
}
static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
@@ -1112,7 +1117,7 @@ static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
if (qdisc_is_percpu_stats(sch)) {
qdisc_qstats_cpu_backlog_dec(sch, skb);
qdisc_bstats_cpu_update(sch, skb);
- qdisc_qstats_atomic_qlen_dec(sch);
+ qdisc_qstats_cpu_qlen_dec(sch);
} else {
qdisc_qstats_backlog_dec(sch, skb);
qdisc_bstats_update(sch, skb);
@@ -1124,7 +1129,7 @@ static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
unsigned int pkt_len)
{
if (qdisc_is_percpu_stats(sch)) {
- qdisc_qstats_atomic_qlen_inc(sch);
+ qdisc_qstats_cpu_qlen_inc(sch);
this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
} else {
sch->qstats.backlog += pkt_len;
@@ -1141,7 +1146,7 @@ static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
skb = __skb_dequeue(&sch->gso_skb);
if (qdisc_is_percpu_stats(sch)) {
qdisc_qstats_cpu_backlog_dec(sch, skb);
- qdisc_qstats_atomic_qlen_dec(sch);
+ qdisc_qstats_cpu_qlen_dec(sch);
} else {
qdisc_qstats_backlog_dec(sch, skb);
sch->q.qlen--;