From 977f1aa5e4d1942bc8012bf3f0e695008979ff4e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 31 Aug 2022 18:44:27 +0000 Subject: net: bql: add more documentation Add some documentation for netdev_tx_sent_queue() and netdev_tx_completed_queue() Stating that netdev_tx_completed_queue() must be called once per TX completion round is apparently not obvious for everybody. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/netdevice.h | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index eec35f9b6616..cfe41c053e11 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3353,6 +3353,16 @@ static inline void netdev_txq_bql_complete_prefetchw(struct netdev_queue *dev_qu #endif } +/** + * netdev_tx_sent_queue - report the number of bytes queued to a given tx queue + * @dev_queue: network device queue + * @bytes: number of bytes queued to the device queue + * + * Report the number of bytes queued for sending/completion to the network + * device hardware queue. @bytes should be a good approximation and should + * exactly match netdev_completed_queue() @bytes. + * This is typically called once per packet, from ndo_start_xmit(). + */ static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue, unsigned int bytes) { @@ -3398,13 +3408,14 @@ static inline bool __netdev_tx_sent_queue(struct netdev_queue *dev_queue, } /** - * netdev_sent_queue - report the number of bytes queued to hardware - * @dev: network device - * @bytes: number of bytes queued to the hardware device queue + * netdev_sent_queue - report the number of bytes queued to hardware + * @dev: network device + * @bytes: number of bytes queued to the hardware device queue * - * Report the number of bytes queued for sending/completion to the network - * device hardware queue. @bytes should be a good approximation and should - * exactly match netdev_completed_queue() @bytes + * Report the number of bytes queued for sending/completion to the network + * device hardware queue#0. @bytes should be a good approximation and should + * exactly match netdev_completed_queue() @bytes. + * This is typically called once per packet, from ndo_start_xmit(). */ static inline void netdev_sent_queue(struct net_device *dev, unsigned int bytes) { @@ -3419,6 +3430,15 @@ static inline bool __netdev_sent_queue(struct net_device *dev, xmit_more); } +/** + * netdev_tx_completed_queue - report number of packets/bytes at TX completion. + * @dev_queue: network device queue + * @pkts: number of packets (currently ignored) + * @bytes: number of bytes dequeued from the device queue + * + * Must be called at most once per TX completion round (and not per + * individual packet), so that BQL can adjust its limits appropriately. + */ static inline void netdev_tx_completed_queue(struct netdev_queue *dev_queue, unsigned int pkts, unsigned int bytes) { -- cgit v1.2.3-59-g8ed1b