From 2c960a5116d05cc7c93d00df707655d72d73d230 Mon Sep 17 00:00:00 2001 From: Matthieu Ternisien d'Ouville Date: Wed, 11 Jan 2017 17:44:01 +0100 Subject: [PATCH] net/mlx: remove link update lock Retrieving link status information through the link update callback should be quick and non-blocking. Mellanox PMDs retrieve this information through ioctl() calls on the related kernel netdevice. This appears to take a long time to complete and may cause significant slowdowns in applications. While these system calls cannot be accelerated, removing the lock on the private structure allows applications to perform other control operations from separate threads in the meantime. This function remains safe without locking as it does not write the private structure, it is only used to retrieve the name of the netdevice. Signed-off-by: Matthieu Ternisien d'Ouville Signed-off-by: Olivier Matz Acked-by: Adrien Mazarguil --- drivers/net/mlx4/mlx4.c | 32 ++++++-------------------------- drivers/net/mlx5/mlx5.c | 2 +- drivers/net/mlx5/mlx5.h | 1 - drivers/net/mlx5/mlx5_ethdev.c | 30 ++++++------------------------ 4 files changed, 13 insertions(+), 52 deletions(-) diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c index eb06f56a08..941176ca7c 100644 --- a/drivers/net/mlx4/mlx4.c +++ b/drivers/net/mlx4/mlx4.c @@ -4823,7 +4823,7 @@ end: } /** - * DPDK callback to retrieve physical link information (unlocked version). + * DPDK callback to retrieve physical link information. * * @param dev * Pointer to Ethernet device structure. @@ -4831,9 +4831,9 @@ end: * Wait for request completion (ignored). */ static int -mlx4_link_update_unlocked(struct rte_eth_dev *dev, int wait_to_complete) +mlx4_link_update(struct rte_eth_dev *dev, int wait_to_complete) { - struct priv *priv = mlx4_get_priv(dev); + const struct priv *priv = mlx4_get_priv(dev); struct ethtool_cmd edata = { .cmd = ETHTOOL_GSET }; @@ -4841,6 +4841,8 @@ mlx4_link_update_unlocked(struct rte_eth_dev *dev, int wait_to_complete) struct rte_eth_link dev_link; int link_speed = 0; + /* priv_lock() is not taken to allow concurrent calls. */ + if (priv == NULL) return -EINVAL; (void)wait_to_complete; @@ -4875,28 +4877,6 @@ mlx4_link_update_unlocked(struct rte_eth_dev *dev, int wait_to_complete) return -1; } -/** - * DPDK callback to retrieve physical link information. - * - * @param dev - * Pointer to Ethernet device structure. - * @param wait_to_complete - * Wait for request completion (ignored). - */ -static int -mlx4_link_update(struct rte_eth_dev *dev, int wait_to_complete) -{ - struct priv *priv = mlx4_get_priv(dev); - int ret; - - if (priv == NULL) - return -EINVAL; - priv_lock(priv); - ret = mlx4_link_update_unlocked(dev, wait_to_complete); - priv_unlock(priv); - return ret; -} - /** * DPDK callback to change the MTU. * @@ -5413,7 +5393,7 @@ priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev) struct rte_eth_link *link = &dev->data->dev_link; priv->pending_alarm = 0; - mlx4_link_update_unlocked(dev, 0); + mlx4_link_update(dev, 0); if (((link->link_speed == 0) && link->link_status) || ((link->link_speed != 0) && !link->link_status)) { /* Inconsistent status, check again later. */ diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index 6293c1fda9..d936e7215e 100644 --- a/drivers/net/mlx5/mlx5.c +++ b/drivers/net/mlx5/mlx5.c @@ -680,7 +680,7 @@ mlx5_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev) /* Bring Ethernet device up. */ DEBUG("forcing Ethernet interface up"); priv_set_flags(priv, ~IFF_UP, IFF_UP); - mlx5_link_update_unlocked(priv->dev, 1); + mlx5_link_update(priv->dev, 1); continue; port_error: diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h index ee62e044e4..d39b19930b 100644 --- a/drivers/net/mlx5/mlx5.h +++ b/drivers/net/mlx5/mlx5.h @@ -194,7 +194,6 @@ int priv_set_flags(struct priv *, unsigned int, unsigned int); int mlx5_dev_configure(struct rte_eth_dev *); void mlx5_dev_infos_get(struct rte_eth_dev *, struct rte_eth_dev_info *); const uint32_t *mlx5_dev_supported_ptypes_get(struct rte_eth_dev *dev); -int mlx5_link_update_unlocked(struct rte_eth_dev *, int); int mlx5_link_update(struct rte_eth_dev *, int); int mlx5_dev_set_mtu(struct rte_eth_dev *, uint16_t); int mlx5_dev_get_flow_ctrl(struct rte_eth_dev *, struct rte_eth_fc_conf *); diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c index fbb1b6566b..a46526ef6d 100644 --- a/drivers/net/mlx5/mlx5_ethdev.c +++ b/drivers/net/mlx5/mlx5_ethdev.c @@ -628,7 +628,7 @@ mlx5_dev_supported_ptypes_get(struct rte_eth_dev *dev) } /** - * Retrieve physical link information (unlocked version using legacy ioctl). + * DPDK callback to retrieve physical link information. * * @param dev * Pointer to Ethernet device structure. @@ -646,6 +646,8 @@ mlx5_link_update_unlocked_gset(struct rte_eth_dev *dev, int wait_to_complete) struct rte_eth_link dev_link; int link_speed = 0; + /* priv_lock() is not taken to allow concurrent calls. */ + (void)wait_to_complete; if (priv_ifreq(priv, SIOCGIFFLAGS, &ifr)) { WARN("ioctl(SIOCGIFFLAGS) failed: %s", strerror(errno)); @@ -790,7 +792,7 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete) } /** - * DPDK callback to retrieve physical link information (unlocked version). + * DPDK callback to retrieve physical link information. * * @param dev * Pointer to Ethernet device structure. @@ -798,7 +800,7 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete) * Wait for request completion (ignored). */ int -mlx5_link_update_unlocked(struct rte_eth_dev *dev, int wait_to_complete) +mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete) { int ret; @@ -808,26 +810,6 @@ mlx5_link_update_unlocked(struct rte_eth_dev *dev, int wait_to_complete) return ret; } -/** - * DPDK callback to retrieve physical link information. - * - * @param dev - * Pointer to Ethernet device structure. - * @param wait_to_complete - * Wait for request completion (ignored). - */ -int -mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete) -{ - struct priv *priv = mlx5_get_priv(dev); - int ret; - - priv_lock(priv); - ret = mlx5_link_update_unlocked(dev, wait_to_complete); - priv_unlock(priv); - return ret; -} - /** * DPDK callback to change the MTU. * @@ -1164,7 +1146,7 @@ priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev) struct rte_eth_link *link = &dev->data->dev_link; priv->pending_alarm = 0; - mlx5_link_update_unlocked(dev, 0); + mlx5_link_update(dev, 0); if (((link->link_speed == 0) && link->link_status) || ((link->link_speed != 0) && !link->link_status)) { /* Inconsistent status, check again later. */ -- 2.20.1