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Merge branch 'net_sched-reflect-tx_queue_len-change-for-pfifo_fast'

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Cong Wang says:

====================
net_sched: reflect tx_queue_len change for pfifo_fast

This pathcset restores the pfifo_fast qdisc behavior of dropping
packets based on latest dev->tx_queue_len. Patch 1 introduces
a helper, patch 2 introduces a new Qdisc ops which is called when
we modify tx_queue_len, patch 3 implements this ops for pfifo_fast.

Please see each patch for details.

---
v3: use skb_array_resize_multiple()
v2: handle error case for ->change_tx_queue_len()
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2018-01-29 12:42:15 -05:00
commit f7dd5215b2
6 changed files with 88 additions and 36 deletions

1
include/linux/netdevice.h

@ -3331,6 +3331,7 @@ int dev_get_alias(const struct net_device *, char *, size_t);
int dev_change_net_namespace(struct net_device *, struct net *, const char *);
int __dev_set_mtu(struct net_device *, int);
int dev_set_mtu(struct net_device *, int);
int dev_change_tx_queue_len(struct net_device *, unsigned long);
void dev_set_group(struct net_device *, int);
int dev_set_mac_address(struct net_device *, struct sockaddr *);
int dev_change_carrier(struct net_device *, bool new_carrier);

2
include/net/sch_generic.h

@ -200,6 +200,7 @@ struct Qdisc_ops {
struct nlattr *arg,
struct netlink_ext_ack *extack);
void (*attach)(struct Qdisc *sch);
int (*change_tx_queue_len)(struct Qdisc *, unsigned int);
int (*dump)(struct Qdisc *, struct sk_buff *);
int (*dump_stats)(struct Qdisc *, struct gnet_dump *);
@ -489,6 +490,7 @@ void qdisc_class_hash_remove(struct Qdisc_class_hash *,
void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
int dev_qdisc_change_tx_queue_len(struct net_device *dev);
void dev_init_scheduler(struct net_device *dev);
void dev_shutdown(struct net_device *dev);
void dev_activate(struct net_device *dev);

29
net/core/dev.c

@ -7047,6 +7047,35 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
}
EXPORT_SYMBOL(dev_set_mtu);
/**
* dev_change_tx_queue_len - Change TX queue length of a netdevice
* @dev: device
* @new_len: new tx queue length
*/
int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
{
unsigned int orig_len = dev->tx_queue_len;
int res;
if (new_len != (unsigned int)new_len)
return -ERANGE;
if (new_len != orig_len) {
dev->tx_queue_len = new_len;
res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
res = notifier_to_errno(res);
if (res) {
netdev_err(dev,
"refused to change device tx_queue_len\n");
dev->tx_queue_len = orig_len;
return res;
}
return dev_qdisc_change_tx_queue_len(dev);
}
return 0;
}
/**
* dev_set_group - Change group this device belongs to
* @dev: device

25
net/core/net-sysfs.c

@ -346,29 +346,6 @@ static ssize_t flags_store(struct device *dev, struct device_attribute *attr,
}
NETDEVICE_SHOW_RW(flags, fmt_hex);
static int change_tx_queue_len(struct net_device *dev, unsigned long new_len)
{
unsigned int orig_len = dev->tx_queue_len;
int res;
if (new_len != (unsigned int)new_len)
return -ERANGE;
if (new_len != orig_len) {
dev->tx_queue_len = new_len;
res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
res = notifier_to_errno(res);
if (res) {
netdev_err(dev,
"refused to change device tx_queue_len\n");
dev->tx_queue_len = orig_len;
return -EFAULT;
}
}
return 0;
}
static ssize_t tx_queue_len_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
@ -376,7 +353,7 @@ static ssize_t tx_queue_len_store(struct device *dev,
if (!capable(CAP_NET_ADMIN))
return -EPERM;
return netdev_store(dev, attr, buf, len, change_tx_queue_len);
return netdev_store(dev, attr, buf, len, dev_change_tx_queue_len);
}
NETDEVICE_SHOW_RW(tx_queue_len, fmt_dec);

16
net/core/rtnetlink.c

@ -2337,19 +2337,11 @@ static int do_setlink(const struct sk_buff *skb,
if (tb[IFLA_TXQLEN]) {
unsigned int value = nla_get_u32(tb[IFLA_TXQLEN]);
unsigned int orig_len = dev->tx_queue_len;
if (dev->tx_queue_len ^ value) {
dev->tx_queue_len = value;
err = call_netdevice_notifiers(
NETDEV_CHANGE_TX_QUEUE_LEN, dev);
err = notifier_to_errno(err);
if (err) {
dev->tx_queue_len = orig_len;
goto errout;
}
status |= DO_SETLINK_MODIFIED;
}
err = dev_change_tx_queue_len(dev, value);
if (err)
goto errout;
status |= DO_SETLINK_MODIFIED;
}
if (tb[IFLA_GSO_MAX_SIZE]) {

51
net/sched/sch_generic.c

@ -763,6 +763,23 @@ static void pfifo_fast_destroy(struct Qdisc *sch)
}
}
static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
unsigned int new_len)
{
struct pfifo_fast_priv *priv = qdisc_priv(sch);
struct skb_array *bands[PFIFO_FAST_BANDS];
int prio;
for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
struct skb_array *q = band2list(priv, prio);
bands[prio] = q;
}
return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len,
GFP_KERNEL);
}
struct Qdisc_ops pfifo_fast_ops __read_mostly = {
.id = "pfifo_fast",
.priv_size = sizeof(struct pfifo_fast_priv),
@ -773,6 +790,7 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
.destroy = pfifo_fast_destroy,
.reset = pfifo_fast_reset,
.dump = pfifo_fast_dump,
.change_tx_queue_len = pfifo_fast_change_tx_queue_len,
.owner = THIS_MODULE,
.static_flags = TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
};
@ -1178,6 +1196,39 @@ void dev_deactivate(struct net_device *dev)
}
EXPORT_SYMBOL(dev_deactivate);
static int qdisc_change_tx_queue_len(struct net_device *dev,
struct netdev_queue *dev_queue)
{
struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
const struct Qdisc_ops *ops = qdisc->ops;
if (ops->change_tx_queue_len)
return ops->change_tx_queue_len(qdisc, dev->tx_queue_len);
return 0;
}
int dev_qdisc_change_tx_queue_len(struct net_device *dev)
{
bool up = dev->flags & IFF_UP;
unsigned int i;
int ret = 0;
if (up)
dev_deactivate(dev);
for (i = 0; i < dev->num_tx_queues; i++) {
ret = qdisc_change_tx_queue_len(dev, &dev->_tx[i]);
/* TODO: revert changes on a partial failure */
if (ret)
break;
}
if (up)
dev_activate(dev);
return ret;
}
static void dev_init_scheduler_queue(struct net_device *dev,
struct netdev_queue *dev_queue,
void *_qdisc)