Commit 58caed3d authored by Jakub Kicinski's avatar Jakub Kicinski

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: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20220502232703.396351-1-kuba@kernel.orgSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7d4e91e0
...@@ -2499,37 +2499,53 @@ static inline void *netdev_priv(const struct net_device *dev) ...@@ -2499,37 +2499,53 @@ static inline void *netdev_priv(const struct net_device *dev)
*/ */
#define NAPI_POLL_WEIGHT 64 #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 * netif_napi_add() - initialize a NAPI context
* @dev: network device * @dev: network device
* @napi: NAPI context * @napi: NAPI context
* @poll: polling function * @poll: polling function
* @weight: default weight * @weight: default weight
* *
* netif_napi_add() must be used to initialize a NAPI context prior to calling * netif_napi_add() must be used to initialize a NAPI context prior to calling
* *any* of the other NAPI-related functions. * *any* of the other NAPI-related functions.
*/ */
void netif_napi_add(struct net_device *dev, struct napi_struct *napi, static inline void
int (*poll)(struct napi_struct *, int), int weight); 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 * netif_napi_add_tx() - initialize a NAPI context to be used for Tx only
* @dev: network device * @dev: network device
* @napi: NAPI context * @napi: NAPI context
* @poll: polling function * @poll: polling function
* @weight: default weight
* *
* This variant of netif_napi_add() should be used from drivers using NAPI * This variant of netif_napi_add() should be used from drivers using NAPI
* to exclusively poll a TX queue. * to exclusively poll a TX queue.
* This will avoid we add it into napi_hash[], thus polluting this hash table. * 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, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int (*poll)(struct napi_struct *, int))
int weight)
{ {
set_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state); netif_napi_add_tx_weight(dev, napi, poll, NAPI_POLL_WEIGHT);
netif_napi_add(dev, napi, poll, weight);
} }
/** /**
......
...@@ -6303,8 +6303,8 @@ int dev_set_threaded(struct net_device *dev, bool threaded) ...@@ -6303,8 +6303,8 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
} }
EXPORT_SYMBOL(dev_set_threaded); EXPORT_SYMBOL(dev_set_threaded);
void netif_napi_add(struct net_device *dev, struct napi_struct *napi, void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int weight) int (*poll)(struct napi_struct *, int), int weight)
{ {
if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state))) if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
return; return;
...@@ -6337,7 +6337,7 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi, ...@@ -6337,7 +6337,7 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
if (dev->threaded && napi_kthread_create(napi)) if (dev->threaded && napi_kthread_create(napi))
dev->threaded = 0; dev->threaded = 0;
} }
EXPORT_SYMBOL(netif_napi_add); EXPORT_SYMBOL(netif_napi_add_weight);
void napi_disable(struct napi_struct *n) void napi_disable(struct napi_struct *n)
{ {
......
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