From 114cf5802165ee93e3ab461c9c505cd94a08b800 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Mon, 28 Nov 2011 16:33:09 +0000 Subject: [PATCH] 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- 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/netdevice.h | 32 ++++++++- net/Kconfig | 6 ++ net/core/dev.c | 3 + net/core/net-sysfs.c | 140 +++++++++++++++++++++++++++++++++++--- 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 #include #include +#include #include #include @@ -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 #include #include +#include #include #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