[PATCH net-next 1/2] net: introduce NAPI_POLL_WEIGHT

[PATCH net-next 1/2] net: introduce NAPI_POLL_WEIGHT

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

Some drivers use a too big NAPI poll weight.

This patch adds a NAPI_POLL_WEIGHT default value
and issues an error message if a driver attempts
to use a bigger weight.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
---
 include/linux/netdevice.h |    5 +++++
 net/core/dev.c            |    3 +++
 2 files changed, 8 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b3d00fa..896eb49 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1475,6 +1475,11 @@ static inline void *netdev_priv(const struct net_device *dev)
  */
 #define SET_NETDEV_DEVTYPE(net, devtype)	((net)->dev.type = (devtype))
 
+/* Default NAPI poll() weight
+ * Device drivers are strongly advised to not use bigger value
+ */
+#define NAPI_POLL_WEIGHT 64
+
 /**
  *	netif_napi_add - initialize a napi context
  *	@dev:  network device
diff --git a/net/core/dev.c b/net/core/dev.c
index a06a7a5..9610389 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4057,6 +4057,9 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
 	napi->gro_list = NULL;
 	napi->skb = NULL;
 	napi->poll = poll;
+	if (weight > NAPI_POLL_WEIGHT)
+		pr_err_once("netif_napi_add() called with weight %d on device %s\n",
+			    weight, dev->name);
 	napi->weight = weight;
 	list_add(&napi->dev_list, &dev->napi_list);
 	napi->dev = dev;

Re: [PATCH net-next 1/2] net: introduce NAPI_POLL_WEIGHT

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 05 Mar 2013 17:57:22 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> Some drivers use a too big NAPI poll weight.
> 
> This patch adds a NAPI_POLL_WEIGHT default value
> and issues an error message if a driver attempts
> to use a bigger weight.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Eilon Greenstein <eilong@broadcom.com>

Applied.