On 1/4/2011 3:18 AM, Jarek Poplawski wrote:
quoted text > On Mon, Jan 03, 2011 at 07:05:58PM -0800, John Fastabend wrote:
>> This implements a mqprio queueing discipline that by default creates
>> a pfifo_fast qdisc per tx queue and provides the needed configuration
>> interface.
>>
>> Using the mqprio qdisc the number of tcs currently in use along
>> with the range of queues alloted to each class can be configured. By
>> default skbs are mapped to traffic classes using the skb priority.
>> This mapping is configurable.
>>
>> Configurable parameters,
>>
>> struct tc_mclass_qopt {
>
> Now *_mqprio here and in the subject of the message.
>
>> __u8 num_tc;
>> __u8 prio_tc_map[16];
>
> s/16/TC_SOMETHING/
>
>> __u8 hw;
>> __u16 count[16];
>> __u16 offset[16];
>> };
>>
>> Here the count/offset pairing give the queue alignment and the
>> prio_tc_map gives the mapping from skb->priority to tc.
>>
>> The hw bit determines if the hardware should configure the count
>> and offset values. If the hardware bit is set then the operation
>> will fail if the hardware does not implement the ndo_setup_tc
>> operation. This is to avoid undetermined states where the hardware
>> may or may not control the queue mapping. Also minimal bounds
>> checking is done on the count/offset to verify a queue does not
>> exceed num_tx_queues and that queue ranges do not overlap. Otherwise
>> it is left to user policy or hardware configuration to create
>> useful mappings.
>>
>> It is expected that hardware QOS schemes can be implemented by
>> creating appropriate mappings of queues in ndo_tc_setup().
>>
>> One expected use case is drivers will use the ndo_setup_tc to map
>> queue ranges onto 802.1Q traffic classes. This provides a generic
>> mechanism to map network traffic onto these traffic classes and
>> removes the need for lower layer drivers to no specifics about
>> traffic types.
>>
>> Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
>> ---
>>
>> include/linux/netdevice.h | 3
>> include/linux/pkt_sched.h | 9 +
>> net/sched/Kconfig | 10 +
>> net/sched/Makefile | 1
>> net/sched/sch_generic.c | 4 +
>> net/sched/sch_mqprio.c | 357 +++++++++++++++++++++++++++++++++++++++++++++
>> 6 files changed, 384 insertions(+), 0 deletions(-)
>> create mode 100644 net/sched/sch_mqprio.c
>>
>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>> index 073c48d..f90a863 100644
>> --- a/include/linux/netdevice.h
>> +++ b/include/linux/netdevice.h
>> @@ -764,6 +764,8 @@ struct netdev_tc_txq {
>> * int (*ndo_set_vf_port)(struct net_device *dev, int vf,
>> * struct nlattr *port[]);
>> * int (*ndo_get_vf_port)(struct net_device *dev, int vf, struct sk_buff *skb);
>> + *
>> + * int (*ndo_setup_tc)(struct net_device *dev, int tc);
>> */
>> #define HAVE_NET_DEVICE_OPS
>> struct net_device_ops {
>> @@ -822,6 +824,7 @@ struct net_device_ops {
>> struct nlattr *port[]);
>> int (*ndo_get_vf_port)(struct net_device *dev,
>> int vf, struct sk_buff *skb);
>> + int (*ndo_setup_tc)(struct net_device *dev, u8 tc);
>> #if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
>> int (*ndo_fcoe_enable)(struct net_device *dev);
>> int (*ndo_fcoe_disable)(struct net_device *dev);
>> diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
>> index 2cfa4bc..8e29fa6 100644
>> --- a/include/linux/pkt_sched.h
>> +++ b/include/linux/pkt_sched.h
>> @@ -481,4 +481,13 @@ struct tc_drr_stats {
>> __u32 deficit;
>> };
>>
>> +/* MCLASS */
>
> /* MQPRIO */
>
>> +struct tc_mqprio_qopt {
>> + __u8 num_tc;
>> + __u8 prio_tc_map[16];
>> + __u8 hw;
>> + __u16 count[16];
>> + __u16 offset[16];
>
> s/16/TC_SOMETHING/
fixed.
quoted text >
>> +};
>> +
>> #endif
>> diff --git a/net/sched/Kconfig b/net/sched/Kconfig
>> index a36270a..e42853b 100644
>> --- a/net/sched/Kconfig
>> +++ b/net/sched/Kconfig
>> @@ -205,6 +205,16 @@ config NET_SCH_DRR
>>
>> If unsure, say N.
>>
>> +config NET_SCH_MQPRIO
>> + tristate "Multi-queue priority scheduler (MQPRIO)"
>> + help
>> + Say Y here if you want to use the Multi-queue Priority scheduler.
>
> We might mention about a proper NIC required.
>
Probably good to add a note here. Although you could use qdisc without NIC support.
quoted text >> +
>> + To compile this driver as a module, choose M here: the module will
>> + be called sch_mqprio.
>> +
>> + If unsure, say N.
>> +
>> config NET_SCH_INGRESS
>> tristate "Ingress Qdisc"
>> depends on NET_CLS_ACT
>> diff --git a/net/sched/Makefile b/net/sched/Makefile
>> index 960f5db..26ce681 100644
>> --- a/net/sched/Makefile
>> +++ b/net/sched/Makefile
>> @@ -32,6 +32,7 @@ obj-$(CONFIG_NET_SCH_MULTIQ) += sch_multiq.o
>> obj-$(CONFIG_NET_SCH_ATM) += sch_atm.o
>> obj-$(CONFIG_NET_SCH_NETEM) += sch_netem.o
>> obj-$(CONFIG_NET_SCH_DRR) += sch_drr.o
>> +obj-$(CONFIG_NET_SCH_MQPRIO) += sch_mqprio.o
>> obj-$(CONFIG_NET_CLS_U32) += cls_u32.o
>> obj-$(CONFIG_NET_CLS_ROUTE4) += cls_route.o
>> obj-$(CONFIG_NET_CLS_FW) += cls_fw.o
>> diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
>> index 34dc598..723b278 100644
>> --- a/net/sched/sch_generic.c
>> +++ b/net/sched/sch_generic.c
>> @@ -540,6 +540,7 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
>> .dump = pfifo_fast_dump,
>> .owner = THIS_MODULE,
>> };
>> +EXPORT_SYMBOL(pfifo_fast_ops);
>>
>> struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
>> struct Qdisc_ops *ops)
>> @@ -674,6 +675,7 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
>>
>> return oqdisc;
>> }
>> +EXPORT_SYMBOL(dev_graft_qdisc);
>>
>> static void attach_one_default_qdisc(struct net_device *dev,
>> struct netdev_queue *dev_queue,
>> @@ -761,6 +763,7 @@ void dev_activate(struct net_device *dev)
>> dev_watchdog_up(dev);
>> }
>> }
>> +EXPORT_SYMBOL(dev_activate);
>>
>> static void dev_deactivate_queue(struct net_device *dev,
>> struct netdev_queue *dev_queue,
>> @@ -840,6 +843,7 @@ void dev_deactivate(struct net_device *dev)
>> list_add(&dev->unreg_list, &single);
>> dev_deactivate_many(&single);
>> }
>> +EXPORT_SYMBOL(dev_deactivate);
>>
>> static void dev_init_scheduler_queue(struct net_device *dev,
>> struct netdev_queue *dev_queue,
>> diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
>> new file mode 100644
>> index 0000000..e9e74c7
>> --- /dev/null
>> +++ b/net/sched/sch_mqprio.c
>> @@ -0,0 +1,357 @@
>> +/*
>> + * net/sched/sch_mqprio.c
>> + *
>> + * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/types.h>
>> +#include <linux/slab.h>
>> +#include <linux/kernel.h>
>> +#include <linux/string.h>
>> +#include <linux/errno.h>
>> +#include <linux/skbuff.h>
>> +#include <net/netlink.h>
>> +#include <net/pkt_sched.h>
>> +#include <net/sch_generic.h>
>> +
>> +struct mqprio_sched {
>> + struct Qdisc **qdiscs;
>> + int hw_owned;
>> +};
>> +
>> +static void mqprio_destroy(struct Qdisc *sch)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + struct mqprio_sched *priv = qdisc_priv(sch);
>> + unsigned int ntx;
>> +
>> + if (!priv->qdiscs)
>> + return;
>> +
>> + for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
>> + qdisc_destroy(priv->qdiscs[ntx]);
>> +
>> + if (priv->hw_owned && dev->netdev_ops->ndo_setup_tc)
>> + dev->netdev_ops->ndo_setup_tc(dev, 0);
>> + else
>> + netdev_set_num_tc(dev, 0);
>
> I'm not sure why this unsetting is needed in case it was set by a
> driver before mqprio was created.
>
ndo_setup_tc(dev,x) is called at init to be symetric I think we need to call it here as well. Otherwise we could leave num_tc set unecessarily. Maybe saving the original value and setting it back to the orignal num_tc would be more correct.
quoted text >> +
>> + kfree(priv->qdiscs);
>> +}
>> +
>> +static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
>> +{
>> + int i, j;
>> +
>> + /* Verify num_tc is not out of max range */
>> + if (qopt->num_tc > TC_MAX_QUEUE)
>> + return -EINVAL;
>> +
>> + for (i = 0; i < qopt->num_tc; i++) {
>> + unsigned int last = qopt->offset[i] + qopt->count[i];
>> + /* Verify the queue offset is in the num tx range */
>> + if (qopt->offset[i] >= dev->num_tx_queues)
>> + return -EINVAL;
>> + /* Verify the queue count is in tx range being equal to the
>> + * num_tx_queues indicates the last queue is in use.
>> + */
>> + else if (last > dev->num_tx_queues)
>> + return -EINVAL;
>> +
>> + /* Verify that the offset and counts do not overlap */
>> + for (j = i + 1; j < qopt->num_tc; j++) {
>> + if (last > qopt->offset[j])
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + struct mqprio_sched *priv = qdisc_priv(sch);
>> + struct netdev_queue *dev_queue;
>> + struct Qdisc *qdisc;
>> + int i, err = -EOPNOTSUPP;
>> + struct tc_mqprio_qopt *qopt = NULL;
>> +
>> + /* Unwind attributes on failure */
>> + u8 unwnd_tc = dev->num_tc;
>> + u8 unwnd_map[TC_BITMASK+1];
>
> u8 unwnd_map[TC_BITMASK + 1];
>
fixed
quoted text >> + struct netdev_tc_txq unwnd_txq[TC_MAX_QUEUE];
>> +
>> + if (sch->parent != TC_H_ROOT)
>> + return -EOPNOTSUPP;
>> +
>> + if (!netif_is_multiqueue(dev))
>> + return -EOPNOTSUPP;
>> +
>> + if (nla_len(opt) < sizeof(*qopt))
>> + return -EINVAL;
>> + qopt = nla_data(opt);
>> +
>> + memcpy(unwnd_map, dev->prio_tc_map, sizeof(unwnd_map));
>> + memcpy(unwnd_txq, dev->tc_to_txq, sizeof(unwnd_txq));
>> +
>> + /* If the mqprio options indicate that hardware should own
>> + * the queue mapping then run ndo_setup_tc if this can not
>> + * be done fail immediately.
>> + */
>> + if (qopt->hw && dev->netdev_ops->ndo_setup_tc) {
>> + priv->hw_owned = 1;
>> + err = dev->netdev_ops->ndo_setup_tc(dev, qopt->num_tc);
>> + if (err)
>> + return err;
>> + } else if (!qopt->hw) {
>> + if (mqprio_parse_opt(dev, qopt))
>> + return -EINVAL;
>> +
>> + if (netdev_set_num_tc(dev, qopt->num_tc))
>> + return -EINVAL;
>> +
>> + for (i = 0; i < qopt->num_tc; i++)
>> + netdev_set_tc_queue(dev, i,
>> + qopt->count[i], qopt->offset[i]);
>> + } else {
>> + return -EINVAL;
>> + }
>> +
>> + /* Always use supplied priority mappings */
>> + for (i = 0; i < TC_BITMASK+1; i++) {
>
> for (i = 0; i < TC_BITMASK + 1; i++) {
>
fixed.
quoted text >> + if (netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i])) {
>> + err = -EINVAL;
>> + goto tc_err;
>> + }
>> + }
>> +
>> + /* pre-allocate qdisc, attachment can't fail */
>> + priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
>> + GFP_KERNEL);
>> + if (priv->qdiscs == NULL) {
>> + err = -ENOMEM;
>> + goto tc_err;
>> + }
>> +
>> + for (i = 0; i < dev->num_tx_queues; i++) {
>> + dev_queue = netdev_get_tx_queue(dev, i);
>> + qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops,
>> + TC_H_MAKE(TC_H_MAJ(sch->handle),
>> + TC_H_MIN(i + 1)));
>> + if (qdisc == NULL) {
>> + err = -ENOMEM;
>> + goto err;
>> + }
>> + qdisc->flags |= TCQ_F_CAN_BYPASS;
>> + priv->qdiscs[i] = qdisc;
>> + }
>> +
>> + sch->flags |= TCQ_F_MQROOT;
>> + return 0;
>> +
>> +err:
>> + mqprio_destroy(sch);
>> +tc_err:
>> + if (priv->hw_owned)
>> + dev->netdev_ops->ndo_setup_tc(dev, unwnd_tc);
>> + else
>> + netdev_set_num_tc(dev, unwnd_tc);
>> +
>> + memcpy(dev->prio_tc_map, unwnd_map, sizeof(unwnd_map));
>> + memcpy(dev->tc_to_txq, unwnd_txq, sizeof(unwnd_txq));
>> +
>> + return err;
>> +}
>> +
>> +static void mqprio_attach(struct Qdisc *sch)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + struct mqprio_sched *priv = qdisc_priv(sch);
>> + struct Qdisc *qdisc;
>> + unsigned int ntx;
>> +
>> + /* Attach underlying qdisc */
>> + for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
>> + qdisc = priv->qdiscs[ntx];
>> + qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc);
>> + if (qdisc)
>> + qdisc_destroy(qdisc);
>> + }
>> + kfree(priv->qdiscs);
>> + priv->qdiscs = NULL;
>> +}
>> +
>> +static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch,
>> + unsigned long cl)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + unsigned long ntx = cl - 1;
>> +
>> + if (ntx >= dev->num_tx_queues)
>> + return NULL;
>> + return netdev_get_tx_queue(dev, ntx);
>> +}
>> +
>> +static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
>> + struct Qdisc **old)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
>> +
>> + if (dev->flags & IFF_UP)
>> + dev_deactivate(dev);
>> +
>> + *old = dev_graft_qdisc(dev_queue, new);
>> +
>> + if (dev->flags & IFF_UP)
>> + dev_activate(dev);
>> +
>> + return 0;
>> +}
>> +
>> +static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + struct mqprio_sched *priv = qdisc_priv(sch);
>> + unsigned char *b = skb_tail_pointer(skb);
>> + struct tc_mqprio_qopt opt;
>> + struct Qdisc *qdisc;
>> + unsigned int i;
>> +
>> + 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 = netdev_get_tx_queue(dev, i)->qdisc;
>> + 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.qlen += qdisc->qstats.qlen;
>> + 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));
>> + }
>> +
>> + opt.num_tc = dev->num_tc;
>> + memcpy(opt.prio_tc_map, dev->prio_tc_map, 16);
>
> s/16/TC_SOMETHING
fixed
quoted text >
>> + opt.hw = priv->hw_owned;
>> +
>> + for (i = 0; i < dev->num_tc; i++) {
>> + opt.count[i] = dev->tc_to_txq[i].count;
>> + opt.offset[i] = dev->tc_to_txq[i].offset;
>> + }
>> +
>> + NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
>> +
>> + return skb->len;
>> +nla_put_failure:
>> + nlmsg_trim(skb, b);
>> + return -1;
>> +}
>> +
>> +static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
>> +{
>> + struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
>> +
>> + return dev_queue->qdisc_sleeping;
>> +}
>> +
>> +static unsigned long mqprio_get(struct Qdisc *sch, u32 classid)
>> +{
>> + unsigned int ntx = TC_H_MIN(classid);
>> +
>> + if (!mqprio_queue_get(sch, ntx))
>> + return 0;
>> + return ntx;
>> +}
>> +
>> +static void mqprio_put(struct Qdisc *sch, unsigned long cl)
>> +{
>> +}
>> +
>> +static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
>> + struct sk_buff *skb, struct tcmsg *tcm)
>> +{
>> + struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
>> +
>> + tcm->tcm_parent = TC_H_ROOT;
>> + tcm->tcm_handle |= TC_H_MIN(cl);
>> + tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
>> + return 0;
>> +}
>> +
>> +static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
>> + struct gnet_dump *d)
>> +{
>> + struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
>> +
>> + sch = dev_queue->qdisc_sleeping;
>> + sch->qstats.qlen = sch->q.qlen;
>> + if (gnet_stats_copy_basic(d, &sch->bstats) < 0 ||
>> + gnet_stats_copy_queue(d, &sch->qstats) < 0)
>> + return -1;
>> + return 0;
>> +}
>> +
>> +static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
>> +{
>> + struct net_device *dev = qdisc_dev(sch);
>> + unsigned long ntx;
>> +
>> + if (arg->stop)
>> + return;
>> +
>> + arg->count = arg->skip;
>> + for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
>
> Did you give up those stats per tc class? You only show the leaf
> classes here, but you could first loop per num_tc (as virtual
> parent classes). So in dump_class_stats you should be able to
> distinguish class 'level' by cl and do the second loop if necessary.
> To show the class hierarchy you change tcm_parent in dump_class
> for 'leaf' classes (like eg in sch_htb/htb_dump_class).
>
I did give up... but got it working with your hint in v5 thanks.
John.
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