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authorTom Herbert <therbert@google.com>2011-11-28 16:33:09 +0000
committerDavid S. Miller <davem@davemloft.net>2011-11-29 12:46:19 -0500
commit114cf5802165ee93e3ab461c9c505cd94a08b800 (patch)
tree88208dddd7c1e90f5e1a840ad0ad7afcea991050
parent927fbec13e40648d3c87cbb1daaac5b1fb9c8775 (diff)
bql: Byte queue limits
Networking stack support for byte queue limits, uses dynamic queue limits library. Byte queue limits are maintained per transmit queue, and a dql structure has been added to netdev_queue structure for this purpose. Configuration of bql is in the tx-<n> sysfs directory for the queue under the byte_queue_limits directory. Configuration includes: limit_min, bql minimum limit limit_max, bql maximum limit hold_time, bql slack hold time Also under the directory are: limit, current byte limit inflight, current number of bytes on the queue Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/netdevice.h32
-rw-r--r--net/Kconfig6
-rw-r--r--net/core/dev.c3
-rw-r--r--net/core/net-sysfs.c140
4 files changed, 172 insertions, 9 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9b24cc7a54d1..97edb3215a5a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -43,6 +43,7 @@
#include <linux/rculist.h>
#include <linux/dmaengine.h>
#include <linux/workqueue.h>
+#include <linux/dynamic_queue_limits.h>
#include <linux/ethtool.h>
#include <net/net_namespace.h>
@@ -541,7 +542,6 @@ struct netdev_queue {
*/
struct net_device *dev;
struct Qdisc *qdisc;
- unsigned long state;
struct Qdisc *qdisc_sleeping;
#ifdef CONFIG_SYSFS
struct kobject kobj;
@@ -564,6 +564,12 @@ struct netdev_queue {
* (/sys/class/net/DEV/Q/trans_timeout)
*/
unsigned long trans_timeout;
+
+ unsigned long state;
+
+#ifdef CONFIG_BQL
+ struct dql dql;
+#endif
} ____cacheline_aligned_in_smp;
static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)
@@ -1862,6 +1868,15 @@ static inline int netif_xmit_frozen_or_stopped(const struct netdev_queue *dev_qu
static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue,
unsigned int bytes)
{
+#ifdef CONFIG_BQL
+ dql_queued(&dev_queue->dql, bytes);
+ if (unlikely(dql_avail(&dev_queue->dql) < 0)) {
+ set_bit(__QUEUE_STATE_STACK_XOFF, &dev_queue->state);
+ if (unlikely(dql_avail(&dev_queue->dql) >= 0))
+ clear_bit(__QUEUE_STATE_STACK_XOFF,
+ &dev_queue->state);
+ }
+#endif
}
static inline void netdev_sent_queue(struct net_device *dev, unsigned int bytes)
@@ -1872,6 +1887,18 @@ static inline void netdev_sent_queue(struct net_device *dev, unsigned int bytes)
static inline void netdev_tx_completed_queue(struct netdev_queue *dev_queue,
unsigned pkts, unsigned bytes)
{
+#ifdef CONFIG_BQL
+ if (likely(bytes)) {
+ dql_completed(&dev_queue->dql, bytes);
+ if (unlikely(test_bit(__QUEUE_STATE_STACK_XOFF,
+ &dev_queue->state) &&
+ dql_avail(&dev_queue->dql) >= 0)) {
+ if (test_and_clear_bit(__QUEUE_STATE_STACK_XOFF,
+ &dev_queue->state))
+ netif_schedule_queue(dev_queue);
+ }
+ }
+#endif
}
static inline void netdev_completed_queue(struct net_device *dev,
@@ -1882,6 +1909,9 @@ static inline void netdev_completed_queue(struct net_device *dev,
static inline void netdev_tx_reset_queue(struct netdev_queue *q)
{
+#ifdef CONFIG_BQL
+ dql_reset(&q->dql);
+#endif
}
static inline void netdev_reset_queue(struct net_device *dev_queue)
diff --git a/net/Kconfig b/net/Kconfig
index 63d2c5dc36ff..2d998735c4d8 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -239,6 +239,12 @@ config NETPRIO_CGROUP
Cgroup subsystem for use in assigning processes to network priorities on
a per-interface basis
+config BQL
+ boolean
+ depends on SYSFS
+ select DQL
+ default y
+
config HAVE_BPF_JIT
bool
diff --git a/net/core/dev.c b/net/core/dev.c
index cb8f753b4238..91a599122074 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5470,6 +5470,9 @@ static void netdev_init_one_queue(struct net_device *dev,
queue->xmit_lock_owner = -1;
netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
queue->dev = dev;
+#ifdef CONFIG_BQL
+ dql_init(&queue->dql, HZ);
+#endif
}
static int netif_alloc_netdev_queues(struct net_device *dev)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index b17c14a0fce9..3bf72b638d34 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -21,6 +21,7 @@
#include <linux/wireless.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
+#include <linux/jiffies.h>
#include <net/wext.h>
#include "net-sysfs.h"
@@ -845,6 +846,116 @@ static ssize_t show_trans_timeout(struct netdev_queue *queue,
static struct netdev_queue_attribute queue_trans_timeout =
__ATTR(tx_timeout, S_IRUGO, show_trans_timeout, NULL);
+#ifdef CONFIG_BQL
+/*
+ * Byte queue limits sysfs structures and functions.
+ */
+static ssize_t bql_show(char *buf, unsigned int value)
+{
+ return sprintf(buf, "%u\n", value);
+}
+
+static ssize_t bql_set(const char *buf, const size_t count,
+ unsigned int *pvalue)
+{
+ unsigned int value;
+ int err;
+
+ if (!strcmp(buf, "max") || !strcmp(buf, "max\n"))
+ value = DQL_MAX_LIMIT;
+ else {
+ err = kstrtouint(buf, 10, &value);
+ if (err < 0)
+ return err;
+ if (value > DQL_MAX_LIMIT)
+ return -EINVAL;
+ }
+
+ *pvalue = value;
+
+ return count;
+}
+
+static ssize_t bql_show_hold_time(struct netdev_queue *queue,
+ struct netdev_queue_attribute *attr,
+ char *buf)
+{
+ struct dql *dql = &queue->dql;
+
+ return sprintf(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time));
+}
+
+static ssize_t bql_set_hold_time(struct netdev_queue *queue,
+ struct netdev_queue_attribute *attribute,
+ const char *buf, size_t len)
+{
+ struct dql *dql = &queue->dql;
+ unsigned value;
+ int err;
+
+ err = kstrtouint(buf, 10, &value);
+ if (err < 0)
+ return err;
+
+ dql->slack_hold_time = msecs_to_jiffies(value);
+
+ return len;
+}
+
+static struct netdev_queue_attribute bql_hold_time_attribute =
+ __ATTR(hold_time, S_IRUGO | S_IWUSR, bql_show_hold_time,
+ bql_set_hold_time);
+
+static ssize_t bql_show_inflight(struct netdev_queue *queue,
+ struct netdev_queue_attribute *attr,
+ char *buf)
+{
+ struct dql *dql = &queue->dql;
+
+ return sprintf(buf, "%u\n", dql->num_queued - dql->num_completed);
+}
+
+static struct netdev_queue_attribute bql_inflight_attribute =
+ __ATTR(inflight, S_IRUGO | S_IWUSR, bql_show_inflight, NULL);
+
+#define BQL_ATTR(NAME, FIELD) \
+static ssize_t bql_show_ ## NAME(struct netdev_queue *queue, \
+ struct netdev_queue_attribute *attr, \
+ char *buf) \
+{ \
+ return bql_show(buf, queue->dql.FIELD); \
+} \
+ \
+static ssize_t bql_set_ ## NAME(struct netdev_queue *queue, \
+ struct netdev_queue_attribute *attr, \
+ const char *buf, size_t len) \
+{ \
+ return bql_set(buf, len, &queue->dql.FIELD); \
+} \
+ \
+static struct netdev_queue_attribute bql_ ## NAME ## _attribute = \
+ __ATTR(NAME, S_IRUGO | S_IWUSR, bql_show_ ## NAME, \
+ bql_set_ ## NAME);
+
+BQL_ATTR(limit, limit)
+BQL_ATTR(limit_max, max_limit)
+BQL_ATTR(limit_min, min_limit)
+
+static struct attribute *dql_attrs[] = {
+ &bql_limit_attribute.attr,
+ &bql_limit_max_attribute.attr,
+ &bql_limit_min_attribute.attr,
+ &bql_hold_time_attribute.attr,
+ &bql_inflight_attribute.attr,
+ NULL
+};
+
+static struct attribute_group dql_group = {
+ .name = "byte_queue_limits",
+ .attrs = dql_attrs,
+};
+#endif /* CONFIG_BQL */
+
#ifdef CONFIG_XPS
static inline unsigned int get_netdev_queue_index(struct netdev_queue *queue)
{
@@ -1096,17 +1207,17 @@ static struct attribute *netdev_queue_default_attrs[] = {
NULL
};
-#ifdef CONFIG_XPS
static void netdev_queue_release(struct kobject *kobj)
{
struct netdev_queue *queue = to_netdev_queue(kobj);
+#ifdef CONFIG_XPS
xps_queue_release(queue);
+#endif
memset(kobj, 0, sizeof(*kobj));
dev_put(queue->dev);
}
-#endif /* CONFIG_XPS */
static struct kobj_type netdev_queue_ktype = {
.sysfs_ops = &netdev_queue_sysfs_ops,
@@ -1125,14 +1236,21 @@ static int netdev_queue_add_kobject(struct net_device *net, int index)
kobj->kset = net->queues_kset;
error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
"tx-%u", index);
- if (error) {
- kobject_put(kobj);
- return error;
- }
+ if (error)
+ goto exit;
+
+#ifdef CONFIG_BQL
+ error = sysfs_create_group(kobj, &dql_group);
+ if (error)
+ goto exit;
+#endif
kobject_uevent(kobj, KOBJ_ADD);
dev_hold(queue->dev);
+ return 0;
+exit:
+ kobject_put(kobj);
return error;
}
#endif /* CONFIG_SYSFS */
@@ -1152,8 +1270,14 @@ netdev_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
}
}
- while (--i >= new_num)
- kobject_put(&net->_tx[i].kobj);
+ while (--i >= new_num) {
+ struct netdev_queue *queue = net->_tx + i;
+
+#ifdef CONFIG_BQL
+ sysfs_remove_group(&queue->kobj, &dql_group);
+#endif
+ kobject_put(&queue->kobj);
+ }
return error;
#else