diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
index d569f2a424d5..9a0319a82470 100644
--- a/Documentation/sysctl/net.txt
+++ b/Documentation/sysctl/net.txt
@@ -50,6 +50,19 @@ The maximum number of packets that kernel can handle on a NAPI interrupt,
it's a Per-CPU variable.
Default: 64
+default_qdisc
+--------------
+
+The default queuing discipline to use for network devices. This allows
+overriding the default queue discipline of pfifo_fast with an
+alternative. Since the default queuing discipline is created with the
+no additional parameters so is best suited to queuing disciplines that
+work well without configuration like stochastic fair queue (sfq),
+CoDel (codel) or fair queue CoDel (fq_codel). Don't use queuing disciplines
+like Hierarchical Token Bucket or Deficit Round Robin which require setting
+up classes and bandwidths.
+Default: pfifo_fast
+
busy_read
----------------
Low latency busy poll timeout for socket reads. (needs CONFIG_NET_RX_BUSY_POLL)
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index f7c24f8fbdc5..59ec3cd15d68 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -85,6 +85,9 @@ struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
int register_qdisc(struct Qdisc_ops *qops);
int unregister_qdisc(struct Qdisc_ops *qops);
+void qdisc_get_default(char *id, size_t len);
+int qdisc_set_default(const char *id);
+
void qdisc_list_del(struct Qdisc *q);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 76368c9d4503..2e31bf14df00 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -316,6 +316,7 @@ extern struct Qdisc noop_qdisc;
extern struct Qdisc_ops noop_qdisc_ops;
extern struct Qdisc_ops pfifo_fast_ops;
extern struct Qdisc_ops mq_qdisc_ops;
+extern const struct Qdisc_ops *default_qdisc_ops;
struct Qdisc_class_common {
u32 classid;
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 31107abd2783..cca444190907 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -20,6 +20,7 @@
#include <net/sock.h>
#include <net/net_ratelimit.h>
#include <net/busy_poll.h>
+#include <net/pkt_sched.h>
static int zero = 0;
static int one = 1;
@@ -193,6 +194,26 @@ static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
}
#endif /* CONFIG_NET_FLOW_LIMIT */
+#ifdef CONFIG_NET_SCHED
+static int set_default_qdisc(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ char id[IFNAMSIZ];
+ struct ctl_table tbl = {
+ .data = id,
+ .maxlen = IFNAMSIZ,
+ };
+ int ret;
+
+ qdisc_get_default(id, IFNAMSIZ);
+
+ ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
+ if (write && ret == 0)
+ ret = qdisc_set_default(id);
+ return ret;
+}
+#endif
+
static struct ctl_table net_core_table[] = {
#ifdef CONFIG_NET
{
@@ -315,7 +336,14 @@ static struct ctl_table net_core_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec
},
-#
+#endif
+#ifdef CONFIG_NET_SCHED
+ {
+ .procname = "default_qdisc",
+ .mode = 0644,
+ .maxlen = IFNAMSIZ,
+ .proc_handler = set_default_qdisc
+ },
#endif
#endif /* CONFIG_NET */
{
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 51b968d3febb..812e57900591 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -131,6 +131,11 @@ static DEFINE_RWLOCK(qdisc_mod_lock);
************************************************/
+/* Qdisc to use by default */
+
+const struct Qdisc_ops *default_qdisc_ops = &pfifo_fast_ops;
+EXPORT_SYMBOL(default_qdisc_ops);
+
/* The list of all installed queueing disciplines. */
static struct Qdisc_ops *qdisc_base;
@@ -200,6 +205,58 @@ int unregister_qdisc(struct Qdisc_ops *qops)
}
EXPORT_SYMBOL(unregister_qdisc);
+/* Get default qdisc if not otherwise specified */
+void qdisc_get_default(char *name, size_t len)
+{
+ read_lock(&qdisc_mod_lock);
+ strlcpy(name, default_qdisc_ops->id, len);
+ read_unlock(&qdisc_mod_lock);
+}
+
+static struct Qdisc_ops *qdisc_lookup_default(const char *name)
+{
+ struct Qdisc_ops *q = NULL;
+
+ for (q = qdisc_base; q; q = q->next) {
+ if (!strcmp(name, q->id)) {
+ if (!try_module_get(q->owner))
+ q = NULL;
+ break;
+ }
+ }
+
+ return q;
+}
+
+/* Set new default qdisc to use */
+int qdisc_set_default(const char *name)
+{
+ const struct Qdisc_ops *ops;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ write_lock(&qdisc_mod_lock);
+ ops = qdisc_lookup_default(name);
+ if (!ops) {
+ /* Not found, drop lock and try to load module */
+ write_unlock(&qdisc_mod_lock);
+ request_module("sch_%s", name);
+ write_lock(&qdisc_mod_lock);
+
+ ops = qdisc_lookup_default(name);
+ }
+
+ if (ops) {
+ /* Set new default */
+ module_put(default_qdisc_ops->owner);
+ default_qdisc_ops = ops;
+ }
+ write_unlock(&qdisc_mod_lock);
+
+ return ops ? 0 : -ENOENT;
+}
+
/* We know handle. Find qdisc among all qdisc's attached to device
(root qdisc, all its children, children of children etc.)
*/
@@ -1854,6 +1911,7 @@ static int __init pktsched_init(void)
return err;
}
+ register_qdisc(&pfifo_fast_ops);
register_qdisc(&pfifo_qdisc_ops);
register_qdisc(&bfifo_qdisc_ops);
register_qdisc(&pfifo_head_drop_qdisc_ops);
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 48be3d5c0d92..5078e0c5db8d 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -530,7 +530,6 @@ struct Qdisc_ops pfifo_fast_ops __read_mostly = {
.dump = pfifo_fast_dump,
.owner = THIS_MODULE,
};
-EXPORT_SYMBOL(pfifo_fast_ops);
static struct lock_class_key qdisc_tx_busylock;
@@ -583,6 +582,9 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
{
struct Qdisc *sch;
+ if (!try_module_get(ops->owner))
+ goto errout;
+
sch = qdisc_alloc(dev_queue, ops);
if (IS_ERR(sch))
goto errout;
@@ -686,7 +688,7 @@ static void attach_one_default_qdisc(struct net_device *dev,
if (dev->tx_queue_len) {
qdisc = qdisc_create_dflt(dev_queue,
- &pfifo_fast_ops, TC_H_ROOT);
+ default_qdisc_ops, TC_H_ROOT);
if (!qdisc) {
netdev_info(dev, "activation failed\n");
return;
@@ -739,9 +741,8 @@ void dev_activate(struct net_device *dev)
int need_watchdog;
/* No queueing discipline is attached to device;
- create default one i.e. pfifo_fast for devices,
- which need queueing and noqueue_qdisc for
- virtual interfaces
+ * create default one for devices, which need queueing
+ * and noqueue_qdisc for virtual interfaces
*/
if (dev->qdisc == &noop_qdisc)
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index 5da78a19ac9a..2e56185736d6 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -57,7 +57,7 @@ static int mq_init(struct Qdisc *sch, struct nlattr *opt)
for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
dev_queue = netdev_get_tx_queue(dev, ntx);
- qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops,
+ qdisc = qdisc_create_dflt(dev_queue, default_qdisc_ops,
TC_H_MAKE(TC_H_MAJ(sch->handle),
TC_H_MIN(ntx + 1)));
if (qdisc == NULL)
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index accec33c454c..d44c868cb537 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -124,7 +124,7 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
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,
+ qdisc = qdisc_create_dflt(dev_queue, default_qdisc_ops,
TC_H_MAKE(TC_H_MAJ(sch->handle),
TC_H_MIN(i + 1)));
if (qdisc == NULL) {