From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: [net-next PATCH 12/14] net: sched: add support for TCQ_F_NOLOCK subqueues to sch_mqprio Date: Thu, 07 Dec 2017 09:57:39 -0800 Message-ID: <20171207175739.5771.12336.stgit@john-Precision-Tower-5810> References: <20171207173500.5771.41198.stgit@john-Precision-Tower-5810> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jiri@resnulli.us, xiyou.wangcong@gmail.com To: willemdebruijn.kernel@gmail.com, daniel@iogearbox.net, eric.dumazet@gmail.com, davem@davemloft.net Return-path: Received: from mail-pf0-f194.google.com ([209.85.192.194]:46501 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbdLGR5y (ORCPT ); Thu, 7 Dec 2017 12:57:54 -0500 Received: by mail-pf0-f194.google.com with SMTP id c204so5218631pfc.13 for ; Thu, 07 Dec 2017 09:57:54 -0800 (PST) In-Reply-To: <20171207173500.5771.41198.stgit@john-Precision-Tower-5810> Sender: netdev-owner@vger.kernel.org List-ID: The sch_mqprio qdisc creates a sub-qdisc per tx queue which are then called independently for enqueue and dequeue operations. However statistics are aggregated and pushed up to the "master" qdisc. This patch adds support for any of the sub-qdiscs to be per cpu statistic qdiscs. To handle this case add a check when calculating stats and aggregate the per cpu stats if needed. Signed-off-by: John Fastabend --- net/sched/sch_mq.c | 35 +++++++++++++++--------- net/sched/sch_mqprio.c | 69 +++++++++++++++++++++++++++++++++--------------- 2 files changed, 69 insertions(+), 35 deletions(-) diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c index bc59f05..8cbb5c8 100644 --- a/net/sched/sch_mq.c +++ b/net/sched/sch_mq.c @@ -98,33 +98,42 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) struct net_device *dev = qdisc_dev(sch); struct Qdisc *qdisc; unsigned int ntx; + __u32 qlen = 0; sch->q.qlen = 0; memset(&sch->bstats, 0, sizeof(sch->bstats)); memset(&sch->qstats, 0, sizeof(sch->qstats)); + /* MQ supports lockless qdiscs. However, statistics accounting needs + * to account for all, none, or a mix of locked and unlocked child + * qdiscs. Percpu stats are added to counters in-band and locking + * qdisc totals are added at end. + */ for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { - struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL; - struct gnet_stats_queue __percpu *cpu_qstats = NULL; - __u32 qlen = 0; - qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; spin_lock_bh(qdisc_lock(qdisc)); if (qdisc_is_percpu_stats(qdisc)) { - cpu_bstats = qdisc->cpu_bstats; - cpu_qstats = qdisc->cpu_qstats; + qlen = qdisc_qlen_sum(qdisc); + __gnet_stats_copy_basic(NULL, &sch->bstats, + qdisc->cpu_bstats, + &qdisc->bstats); + __gnet_stats_copy_queue(&sch->qstats, + qdisc->cpu_qstats, + &qdisc->qstats, qlen); + } else { + sch->q.qlen += qdisc->q.qlen; + sch->bstats.bytes += qdisc->bstats.bytes; + sch->bstats.packets += qdisc->bstats.packets; + sch->qstats.backlog += qdisc->qstats.backlog; + sch->qstats.drops += qdisc->qstats.drops; + sch->qstats.requeues += qdisc->qstats.requeues; + sch->qstats.overlimits += qdisc->qstats.overlimits; } - qlen = qdisc_qlen_sum(qdisc); - - __gnet_stats_copy_basic(NULL, &sch->bstats, - cpu_bstats, &qdisc->bstats); - __gnet_stats_copy_queue(&sch->qstats, - cpu_qstats, &qdisc->qstats, qlen); - spin_unlock_bh(qdisc_lock(qdisc)); } + return 0; } diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c index b85885a9..8622745 100644 --- a/net/sched/sch_mqprio.c +++ b/net/sched/sch_mqprio.c @@ -388,22 +388,40 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb); struct tc_mqprio_qopt opt = { 0 }; struct Qdisc *qdisc; - unsigned int i; + unsigned int ntx, tc; sch->q.qlen = 0; memset(&sch->bstats, 0, sizeof(sch->bstats)); memset(&sch->qstats, 0, sizeof(sch->qstats)); - for (i = 0; i < dev->num_tx_queues; i++) { - qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); + /* MQ supports lockless qdiscs. However, statistics accounting needs + * to account for all, none, or a mix of locked and unlocked child + * qdiscs. Percpu stats are added to counters in-band and locking + * qdisc totals are added at end. + */ + for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { + qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; spin_lock_bh(qdisc_lock(qdisc)); - sch->q.qlen += qdisc->q.qlen; - sch->bstats.bytes += qdisc->bstats.bytes; - sch->bstats.packets += qdisc->bstats.packets; - sch->qstats.backlog += qdisc->qstats.backlog; - sch->qstats.drops += qdisc->qstats.drops; - sch->qstats.requeues += qdisc->qstats.requeues; - sch->qstats.overlimits += qdisc->qstats.overlimits; + + if (qdisc_is_percpu_stats(qdisc)) { + __u32 qlen = qdisc_qlen_sum(qdisc); + + __gnet_stats_copy_basic(NULL, &sch->bstats, + qdisc->cpu_bstats, + &qdisc->bstats); + __gnet_stats_copy_queue(&sch->qstats, + qdisc->cpu_qstats, + &qdisc->qstats, qlen); + } else { + sch->q.qlen += qdisc->q.qlen; + sch->bstats.bytes += qdisc->bstats.bytes; + sch->bstats.packets += qdisc->bstats.packets; + sch->qstats.backlog += qdisc->qstats.backlog; + sch->qstats.drops += qdisc->qstats.drops; + sch->qstats.requeues += qdisc->qstats.requeues; + sch->qstats.overlimits += qdisc->qstats.overlimits; + } + spin_unlock_bh(qdisc_lock(qdisc)); } @@ -411,9 +429,9 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map)); opt.hw = priv->hw_offload; - for (i = 0; i < netdev_get_num_tc(dev); i++) { - opt.count[i] = dev->tc_to_txq[i].count; - opt.offset[i] = dev->tc_to_txq[i].offset; + for (tc = 0; tc < netdev_get_num_tc(dev); tc++) { + opt.count[tc] = dev->tc_to_txq[tc].count; + opt.offset[tc] = dev->tc_to_txq[tc].offset; } if (nla_put(skb, TCA_OPTIONS, NLA_ALIGN(sizeof(opt)), &opt)) @@ -495,7 +513,6 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, if (cl >= TC_H_MIN_PRIORITY) { int i; __u32 qlen = 0; - struct Qdisc *qdisc; struct gnet_stats_queue qstats = {0}; struct gnet_stats_basic_packed bstats = {0}; struct net_device *dev = qdisc_dev(sch); @@ -511,18 +528,26 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, for (i = tc.offset; i < tc.offset + tc.count; i++) { struct netdev_queue *q = netdev_get_tx_queue(dev, i); + struct Qdisc *qdisc = rtnl_dereference(q->qdisc); + struct gnet_stats_basic_cpu __percpu *cpu_bstats = NULL; + struct gnet_stats_queue __percpu *cpu_qstats = NULL; - qdisc = rtnl_dereference(q->qdisc); spin_lock_bh(qdisc_lock(qdisc)); - qlen += qdisc->q.qlen; - bstats.bytes += qdisc->bstats.bytes; - bstats.packets += qdisc->bstats.packets; - qstats.backlog += qdisc->qstats.backlog; - qstats.drops += qdisc->qstats.drops; - qstats.requeues += qdisc->qstats.requeues; - qstats.overlimits += qdisc->qstats.overlimits; + if (qdisc_is_percpu_stats(qdisc)) { + cpu_bstats = qdisc->cpu_bstats; + cpu_qstats = qdisc->cpu_qstats; + } + + qlen = qdisc_qlen_sum(qdisc); + __gnet_stats_copy_basic(NULL, &sch->bstats, + cpu_bstats, &qdisc->bstats); + __gnet_stats_copy_queue(&sch->qstats, + cpu_qstats, + &qdisc->qstats, + qlen); spin_unlock_bh(qdisc_lock(qdisc)); } + /* Reclaim root sleeping lock before completing stats */ if (d->lock) spin_lock_bh(d->lock);