diff mbox series

[net-next,v4,02/10] net: Add queue and napi association

Message ID 169658368866.3683.5936758786055991674.stgit@anambiarhost.jf.intel.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Introduce queue and NAPI support in netdev-genl (Was: Introduce NAPI queues support) | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5508 this patch: 5508
netdev/cc_maintainers warning 4 maintainers not CCed: edumazet@google.com pabeni@redhat.com daniel@iogearbox.net davem@davemloft.net
netdev/build_clang fail Errors and warnings before: 312 this patch: 312
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 4517 this patch: 4517
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 65 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Nambiar, Amritha Oct. 6, 2023, 9:14 a.m. UTC 
Add the napi pointer in netdev queue for tracking the napi
instance for each queue. This achieves the queue<->napi mapping.

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
 include/linux/netdevice.h     |    5 +++++
 include/net/netdev_rx_queue.h |    2 ++
 net/core/dev.c                |   34 ++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+)

Comments

Jakub Kicinski Oct. 11, 2023, 2:17 a.m. UTC | #1 
On Fri, 06 Oct 2023 02:14:48 -0700 Amritha Nambiar wrote:
>  #endif
> +	/* NAPI instance for the queue */
> +	struct napi_struct		*napi;

What's the protection on this field?
Writers and readers must be under rtnl_lock?

>  } ____cacheline_aligned_in_smp;
>  
>  /*
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 606a366cc209..9b63a7b76c01 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -6394,6 +6394,40 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
>  }
>  EXPORT_SYMBOL(dev_set_threaded);
>  
> +/**
> + * netif_queue_set_napi - Associate queue with the napi
> + * @queue_index: Index of queue
> + * @type: queue type as RX or TX
> + * @napi: NAPI context
> + *
> + * Set queue with its corresponding napi context

Let's add more relevant info, like the fact that NAPI must already be
added before calling, calling context, etc.

> + */
> +int netif_queue_set_napi(unsigned int queue_index, enum netdev_queue_type type,
> +			 struct napi_struct *napi)

Let's make this helper void.
It will be a PITA for callers to handle any error this may return.

> +{
> +	struct net_device *dev = napi->dev;
> +	struct netdev_rx_queue *rxq;
> +	struct netdev_queue *txq;
> +
> +	if (!dev)
> +		return -EINVAL;

	if (WARN_ON_ONCE(...))
		return;

> +	default:
> +		return -EINVAL;
> +	}

same here
Nambiar, Amritha Oct. 11, 2023, 11:36 p.m. UTC | #2 
On 10/10/2023 7:17 PM, Jakub Kicinski wrote:
> On Fri, 06 Oct 2023 02:14:48 -0700 Amritha Nambiar wrote:
>>   #endif
>> +	/* NAPI instance for the queue */
>> +	struct napi_struct		*napi;
> 
> What's the protection on this field?
> Writers and readers must be under rtnl_lock?
> 

Yes, writers and readers must be under rtnl_lock. I will modify 
netif_queue_set_napi() for rtnl protection from writers. Readers are 
holding rtnl_lock.

>>   } ____cacheline_aligned_in_smp;
>>   
>>   /*
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index 606a366cc209..9b63a7b76c01 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -6394,6 +6394,40 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
>>   }
>>   EXPORT_SYMBOL(dev_set_threaded);
>>   
>> +/**
>> + * netif_queue_set_napi - Associate queue with the napi
>> + * @queue_index: Index of queue
>> + * @type: queue type as RX or TX
>> + * @napi: NAPI context
>> + *
>> + * Set queue with its corresponding napi context
> 
> Let's add more relevant info, like the fact that NAPI must already be
> added before calling, calling context, etc.
> 

Okay, will fix in v5.

>> + */
>> +int netif_queue_set_napi(unsigned int queue_index, enum netdev_queue_type type,
>> +			 struct napi_struct *napi)
> 
> Let's make this helper void.
> It will be a PITA for callers to handle any error this may return.
> 

Okay, will make this a void function in v5.

>> +{
>> +	struct net_device *dev = napi->dev;
>> +	struct netdev_rx_queue *rxq;
>> +	struct netdev_queue *txq;
>> +
>> +	if (!dev)
>> +		return -EINVAL;
> 
> 	if (WARN_ON_ONCE(...))
> 		return;
> 
>> +	default:
>> +		return -EINVAL;
>> +	}
> 
> same here

Will fix in v5.
diff mbox series

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e070a4540fba..264ae0bdabe8 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -645,6 +645,8 @@  struct netdev_queue {
 #ifdef CONFIG_XDP_SOCKETS
 	struct xsk_buff_pool    *pool;
 #endif
+	/* NAPI instance for the queue */
+	struct napi_struct      *napi;
 /*
  * write-mostly part
  */
@@ -2619,6 +2621,9 @@  static inline void *netdev_priv(const struct net_device *dev)
  */
 #define SET_NETDEV_DEVTYPE(net, devtype)	((net)->dev.type = (devtype))
 
+int netif_queue_set_napi(unsigned int queue_index, enum netdev_queue_type type,
+			 struct napi_struct *napi);
+
 /* Default NAPI poll() weight
  * Device drivers are strongly advised to not use bigger value
  */
diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index cdcafb30d437..2e65b03d214d 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -21,6 +21,8 @@  struct netdev_rx_queue {
 #ifdef CONFIG_XDP_SOCKETS
 	struct xsk_buff_pool            *pool;
 #endif
+	/* NAPI instance for the queue */
+	struct napi_struct		*napi;
 } ____cacheline_aligned_in_smp;
 
 /*
diff --git a/net/core/dev.c b/net/core/dev.c
index 606a366cc209..9b63a7b76c01 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6394,6 +6394,40 @@  int dev_set_threaded(struct net_device *dev, bool threaded)
 }
 EXPORT_SYMBOL(dev_set_threaded);
 
+/**
+ * netif_queue_set_napi - Associate queue with the napi
+ * @queue_index: Index of queue
+ * @type: queue type as RX or TX
+ * @napi: NAPI context
+ *
+ * Set queue with its corresponding napi context
+ */
+int netif_queue_set_napi(unsigned int queue_index, enum netdev_queue_type type,
+			 struct napi_struct *napi)
+{
+	struct net_device *dev = napi->dev;
+	struct netdev_rx_queue *rxq;
+	struct netdev_queue *txq;
+
+	if (!dev)
+		return -EINVAL;
+
+	switch (type) {
+	case NETDEV_QUEUE_TYPE_RX:
+		rxq = __netif_get_rx_queue(dev, queue_index);
+		rxq->napi = napi;
+		break;
+	case NETDEV_QUEUE_TYPE_TX:
+		txq = netdev_get_tx_queue(dev, queue_index);
+		txq->napi = napi;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(netif_queue_set_napi);
+
 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
 			   int (*poll)(struct napi_struct *, int), int weight)
 {