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>
This commit is contained in:
Tom Herbert
2011-11-28 16:33:09 +00:00
committed by David S. Miller
parent 927fbec13e
commit 114cf58021
4 changed files with 172 additions and 9 deletions

View File

@@ -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)