diff options
| -rw-r--r-- | Documentation/networking/netdev-features.txt | 10 | ||||
| -rw-r--r-- | Documentation/networking/netdevices.txt | 9 | ||||
| -rw-r--r-- | include/linux/netdevice.h | 3 | ||||
| -rw-r--r-- | net/core/net-procfs.c | 3 | ||||
| -rw-r--r-- | net/core/pktgen.c | 1 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 32 |
6 files changed, 9 insertions, 49 deletions
diff --git a/Documentation/networking/netdev-features.txt b/Documentation/networking/netdev-features.txt index f310edec8a77..7413eb05223b 100644 --- a/Documentation/networking/netdev-features.txt +++ b/Documentation/networking/netdev-features.txt @@ -131,13 +131,11 @@ stack. Driver should not change behaviour based on them. * LLTX driver (deprecated for hardware drivers) -NETIF_F_LLTX should be set in drivers that implement their own locking in -transmit path or don't need locking at all (e.g. software tunnels). -In ndo_start_xmit, it is recommended to use a try_lock and return -NETDEV_TX_LOCKED when the spin lock fails. The locking should also properly -protect against other callbacks (the rules you need to find out). +NETIF_F_LLTX is meant to be used by drivers that don't need locking at all, +e.g. software tunnels. -Don't use it for new drivers. +This is also used in a few legacy drivers that implement their +own locking, don't use it for new (hardware) drivers. * netns-local device diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt index 0b1cf6b2a592..7fec2061a334 100644 --- a/Documentation/networking/netdevices.txt +++ b/Documentation/networking/netdevices.txt @@ -69,10 +69,9 @@ ndo_start_xmit: When the driver sets NETIF_F_LLTX in dev->features this will be called without holding netif_tx_lock. In this case the driver - has to lock by itself when needed. It is recommended to use a try lock - for this and return NETDEV_TX_LOCKED when the spin lock fails. - The locking there should also properly protect against - set_rx_mode. Note that the use of NETIF_F_LLTX is deprecated. + has to lock by itself when needed. + The locking there should also properly protect against + set_rx_mode. WARNING: use of NETIF_F_LLTX is deprecated. Don't use it for new drivers. Context: Process with BHs disabled or BH (timer), @@ -83,8 +82,6 @@ ndo_start_xmit: o NETDEV_TX_BUSY Cannot transmit packet, try later Usually a bug, means queue start/stop flow control is broken in the driver. Note: the driver must NOT put the skb in its DMA ring. - o NETDEV_TX_LOCKED Locking failed, please retry quickly. - Only valid when NETIF_F_LLTX is set. ndo_tx_timeout: Synchronization: netif_tx_lock spinlock; all TX queues frozen. diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 1f6d5db471a2..18d8394f2e5d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -106,7 +106,6 @@ enum netdev_tx { __NETDEV_TX_MIN = INT_MIN, /* make sure enum is signed */ NETDEV_TX_OK = 0x00, /* driver took care of packet */ NETDEV_TX_BUSY = 0x10, /* driver tx path was busy*/ - NETDEV_TX_LOCKED = 0x20, /* driver tx lock was already taken */ }; typedef enum netdev_tx netdev_tx_t; @@ -831,7 +830,6 @@ struct tc_to_netdev { * the queue before that can happen; it's for obsolete devices and weird * corner cases, but the stack really does a non-trivial amount * of useless work if you return NETDEV_TX_BUSY. - * (can also return NETDEV_TX_LOCKED iff NETIF_F_LLTX) * Required; cannot be NULL. * * netdev_features_t (*ndo_fix_features)(struct net_device *dev, @@ -2737,7 +2735,6 @@ struct softnet_data { /* stats */ unsigned int processed; unsigned int time_squeeze; - unsigned int cpu_collision; unsigned int received_rps; #ifdef CONFIG_RPS struct softnet_data *rps_ipi_list; diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 2bf83299600a..14d09345f00d 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -162,7 +162,8 @@ static int softnet_seq_show(struct seq_file *seq, void *v) "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n", sd->processed, sd->dropped, sd->time_squeeze, 0, 0, 0, 0, 0, /* was fastroute */ - sd->cpu_collision, sd->received_rps, flow_limit_count); + 0, /* was cpu_collision */ + sd->received_rps, flow_limit_count); return 0; } diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 20999aa596dd..8604ae245960 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -3472,7 +3472,6 @@ xmit_more: pkt_dev->odevname, ret); pkt_dev->errors++; /* fallthru */ - case NETDEV_TX_LOCKED: case NETDEV_TX_BUSY: /* Retry it next time */ atomic_dec(&(pkt_dev->skb->users)); diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 80742edea96f..9c7756237904 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -108,35 +108,6 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, return skb; } -static inline int handle_dev_cpu_collision(struct sk_buff *skb, - struct netdev_queue *dev_queue, - struct Qdisc *q) -{ - int ret; - - if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) { - /* - * Same CPU holding the lock. It may be a transient - * configuration error, when hard_start_xmit() recurses. We - * detect it by checking xmit owner and drop the packet when - * deadloop is detected. Return OK to try the next skb. - */ - kfree_skb_list(skb); - net_warn_ratelimited("Dead loop on netdevice %s, fix it urgently!\n", - dev_queue->dev->name); - ret = qdisc_qlen(q); - } else { - /* - * Another cpu is holding lock, requeue & delay xmits for - * some time. - */ - __this_cpu_inc(softnet_data.cpu_collision); - ret = dev_requeue_skb(skb, q); - } - - return ret; -} - /* * Transmit possibly several skbs, and handle the return status as * required. Holding the __QDISC___STATE_RUNNING bit guarantees that @@ -174,9 +145,6 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, if (dev_xmit_complete(ret)) { /* Driver sent out skb successfully or skb was consumed */ ret = qdisc_qlen(q); - } else if (ret == NETDEV_TX_LOCKED) { - /* Driver try lock failed */ - ret = handle_dev_cpu_collision(skb, txq, q); } else { /* Driver returned NETDEV_TX_BUSY - requeue skb */ if (unlikely(ret != NETDEV_TX_BUSY)) |