mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
![WANG Cong](/assets/img/avatar_default.png)
For TC classes, their ->get() and ->put() are always paired, and the reference counting is completely useless, because: 1) For class modification and dumping paths, we already hold RTNL lock, so all of these ->get(),->change(),->put() are atomic. 2) For filter bindiing/unbinding, we use other reference counter than this one, and they should have RTNL lock too. 3) For ->qlen_notify(), it is special because it is called on ->enqueue() path, but we already hold qdisc tree lock there, and we hold this tree lock when graft or delete the class too, so it should not be gone or changed until we release the tree lock. Therefore, this patch removes ->get() and ->put(), but: 1) Adds a new ->find() to find the pointer to a class by classid, no refcnt. 2) Move the original class destroy upon the last refcnt into ->delete(), right after releasing tree lock. This is fine because the class is already removed from hash when holding the lock. For those who also use ->put() as ->unbind(), just rename them to reflect this change. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
237 lines
5.7 KiB
C
237 lines
5.7 KiB
C
/*
|
|
* net/sched/sch_mq.c Classful multiqueue dummy scheduler
|
|
*
|
|
* Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* 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/export.h>
|
|
#include <linux/string.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/skbuff.h>
|
|
#include <net/netlink.h>
|
|
#include <net/pkt_sched.h>
|
|
|
|
struct mq_sched {
|
|
struct Qdisc **qdiscs;
|
|
};
|
|
|
|
static void mq_destroy(struct Qdisc *sch)
|
|
{
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
struct mq_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]);
|
|
kfree(priv->qdiscs);
|
|
}
|
|
|
|
static int mq_init(struct Qdisc *sch, struct nlattr *opt)
|
|
{
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
struct mq_sched *priv = qdisc_priv(sch);
|
|
struct netdev_queue *dev_queue;
|
|
struct Qdisc *qdisc;
|
|
unsigned int ntx;
|
|
|
|
if (sch->parent != TC_H_ROOT)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (!netif_is_multiqueue(dev))
|
|
return -EOPNOTSUPP;
|
|
|
|
/* pre-allocate qdiscs, attachment can't fail */
|
|
priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
|
|
GFP_KERNEL);
|
|
if (!priv->qdiscs)
|
|
return -ENOMEM;
|
|
|
|
for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
|
|
dev_queue = netdev_get_tx_queue(dev, ntx);
|
|
qdisc = qdisc_create_dflt(dev_queue, get_default_qdisc_ops(dev, ntx),
|
|
TC_H_MAKE(TC_H_MAJ(sch->handle),
|
|
TC_H_MIN(ntx + 1)));
|
|
if (!qdisc)
|
|
return -ENOMEM;
|
|
priv->qdiscs[ntx] = qdisc;
|
|
qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
|
|
}
|
|
|
|
sch->flags |= TCQ_F_MQROOT;
|
|
return 0;
|
|
}
|
|
|
|
static void mq_attach(struct Qdisc *sch)
|
|
{
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
struct mq_sched *priv = qdisc_priv(sch);
|
|
struct Qdisc *qdisc, *old;
|
|
unsigned int ntx;
|
|
|
|
for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
|
|
qdisc = priv->qdiscs[ntx];
|
|
old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
|
|
if (old)
|
|
qdisc_destroy(old);
|
|
#ifdef CONFIG_NET_SCHED
|
|
if (ntx < dev->real_num_tx_queues)
|
|
qdisc_hash_add(qdisc, false);
|
|
#endif
|
|
|
|
}
|
|
kfree(priv->qdiscs);
|
|
priv->qdiscs = NULL;
|
|
}
|
|
|
|
static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
|
|
{
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
struct Qdisc *qdisc;
|
|
unsigned int ntx;
|
|
|
|
sch->q.qlen = 0;
|
|
memset(&sch->bstats, 0, sizeof(sch->bstats));
|
|
memset(&sch->qstats, 0, sizeof(sch->qstats));
|
|
|
|
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;
|
|
spin_unlock_bh(qdisc_lock(qdisc));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct netdev_queue *mq_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 struct netdev_queue *mq_select_queue(struct Qdisc *sch,
|
|
struct tcmsg *tcm)
|
|
{
|
|
unsigned int ntx = TC_H_MIN(tcm->tcm_parent);
|
|
struct netdev_queue *dev_queue = mq_queue_get(sch, ntx);
|
|
|
|
if (!dev_queue) {
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
|
|
return netdev_get_tx_queue(dev, 0);
|
|
}
|
|
return dev_queue;
|
|
}
|
|
|
|
static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
|
|
struct Qdisc **old)
|
|
{
|
|
struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
|
|
if (dev->flags & IFF_UP)
|
|
dev_deactivate(dev);
|
|
|
|
*old = dev_graft_qdisc(dev_queue, new);
|
|
if (new)
|
|
new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
|
|
if (dev->flags & IFF_UP)
|
|
dev_activate(dev);
|
|
return 0;
|
|
}
|
|
|
|
static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
|
|
{
|
|
struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
|
|
|
|
return dev_queue->qdisc_sleeping;
|
|
}
|
|
|
|
static unsigned long mq_find(struct Qdisc *sch, u32 classid)
|
|
{
|
|
unsigned int ntx = TC_H_MIN(classid);
|
|
|
|
if (!mq_queue_get(sch, ntx))
|
|
return 0;
|
|
return ntx;
|
|
}
|
|
|
|
static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
|
|
struct sk_buff *skb, struct tcmsg *tcm)
|
|
{
|
|
struct netdev_queue *dev_queue = mq_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 mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
|
|
struct gnet_dump *d)
|
|
{
|
|
struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
|
|
|
|
sch = dev_queue->qdisc_sleeping;
|
|
if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
|
|
gnet_stats_copy_queue(d, NULL, &sch->qstats, sch->q.qlen) < 0)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
|
|
{
|
|
struct net_device *dev = qdisc_dev(sch);
|
|
unsigned int ntx;
|
|
|
|
if (arg->stop)
|
|
return;
|
|
|
|
arg->count = arg->skip;
|
|
for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
|
|
if (arg->fn(sch, ntx + 1, arg) < 0) {
|
|
arg->stop = 1;
|
|
break;
|
|
}
|
|
arg->count++;
|
|
}
|
|
}
|
|
|
|
static const struct Qdisc_class_ops mq_class_ops = {
|
|
.select_queue = mq_select_queue,
|
|
.graft = mq_graft,
|
|
.leaf = mq_leaf,
|
|
.find = mq_find,
|
|
.walk = mq_walk,
|
|
.dump = mq_dump_class,
|
|
.dump_stats = mq_dump_class_stats,
|
|
};
|
|
|
|
struct Qdisc_ops mq_qdisc_ops __read_mostly = {
|
|
.cl_ops = &mq_class_ops,
|
|
.id = "mq",
|
|
.priv_size = sizeof(struct mq_sched),
|
|
.init = mq_init,
|
|
.destroy = mq_destroy,
|
|
.attach = mq_attach,
|
|
.dump = mq_dump,
|
|
.owner = THIS_MODULE,
|
|
};
|