From 58caed3dacb4354a25a1aa8d2febc3e9648ba1f4 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 2 May 2022 16:27:03 -0700 Subject: [PATCH] netdev: reshuffle netif_napi_add() APIs to allow dropping weight Most drivers should not have to worry about selecting the right weight for their NAPI instances and pass NAPI_POLL_WEIGHT. It'd be best if we didn't require the argument at all and selected the default internally. This change prepares the ground for such reshuffling, allowing for a smooth transition. The following API should remain after the next release cycle: netif_napi_add() netif_napi_add_weight() netif_napi_add_tx() netif_napi_add_tx_weight() Where the _weight() variants take an explicit weight argument. I opted for a _weight() suffix rather than a __ prefix, because we use __ in places to mean that caller needs to also issue a synchronize_net() call. Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20220502232703.396351-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 50 +++++++++++++++++++++++++++++++---------------- net/core/dev.c | 6 +++--- 2 files changed, 36 insertions(+), 20 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 4aba92a4042a..eaf66e57d891 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2499,37 +2499,53 @@ static inline void *netdev_priv(const struct net_device *dev) */ #define NAPI_POLL_WEIGHT 64 +void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi, + int (*poll)(struct napi_struct *, int), int weight); + /** - * netif_napi_add - initialize a NAPI context - * @dev: network device - * @napi: NAPI context - * @poll: polling function - * @weight: default weight + * netif_napi_add() - initialize a NAPI context + * @dev: network device + * @napi: NAPI context + * @poll: polling function + * @weight: default weight * * netif_napi_add() must be used to initialize a NAPI context prior to calling * *any* of the other NAPI-related functions. */ -void netif_napi_add(struct net_device *dev, struct napi_struct *napi, - int (*poll)(struct napi_struct *, int), int weight); +static inline void +netif_napi_add(struct net_device *dev, struct napi_struct *napi, + int (*poll)(struct napi_struct *, int), int weight) +{ + netif_napi_add_weight(dev, napi, poll, weight); +} + +static inline void +netif_napi_add_tx_weight(struct net_device *dev, + struct napi_struct *napi, + int (*poll)(struct napi_struct *, int), + int weight) +{ + set_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state); + netif_napi_add_weight(dev, napi, poll, weight); +} + +#define netif_tx_napi_add netif_napi_add_tx_weight /** - * netif_tx_napi_add - initialize a NAPI context - * @dev: network device - * @napi: NAPI context - * @poll: polling function - * @weight: default weight + * netif_napi_add_tx() - initialize a NAPI context to be used for Tx only + * @dev: network device + * @napi: NAPI context + * @poll: polling function * * This variant of netif_napi_add() should be used from drivers using NAPI * to exclusively poll a TX queue. * This will avoid we add it into napi_hash[], thus polluting this hash table. */ -static inline void netif_tx_napi_add(struct net_device *dev, +static inline void netif_napi_add_tx(struct net_device *dev, struct napi_struct *napi, - int (*poll)(struct napi_struct *, int), - int weight) + int (*poll)(struct napi_struct *, int)) { - set_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state); - netif_napi_add(dev, napi, poll, weight); + netif_napi_add_tx_weight(dev, napi, poll, NAPI_POLL_WEIGHT); } /** diff --git a/net/core/dev.c b/net/core/dev.c index d127164771f2..c2d73595a7c3 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6303,8 +6303,8 @@ int dev_set_threaded(struct net_device *dev, bool threaded) } EXPORT_SYMBOL(dev_set_threaded); -void netif_napi_add(struct net_device *dev, struct napi_struct *napi, - int (*poll)(struct napi_struct *, int), int weight) +void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi, + int (*poll)(struct napi_struct *, int), int weight) { if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state))) return; @@ -6337,7 +6337,7 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi, if (dev->threaded && napi_kthread_create(napi)) dev->threaded = 0; } -EXPORT_SYMBOL(netif_napi_add); +EXPORT_SYMBOL(netif_napi_add_weight); void napi_disable(struct napi_struct *n) { -- 2.11.0