can: fix NOHZ local_softirq_pending 08 warning (481a8199) · Commits · 戴 / test

When using nanosleep() in an userspace application we get a ratelimit warning NOHZ: local_softirq_pending 08 for 10 times. The echo of CAN frames is done from process context and softirq context only. Therefore the usage of netif_rx() was wrong (for years). This patch replaces netif_rx() with netif_rx_ni() which has to be used from process/softirq context. It also adds a missing comment that can_send() must no be used from hardirq context. Signed-off-by:

Oliver Hartkopp <oliver@hartkopp.net> Signed-off-by:

Urs Thuermann <urs@isnogud.escape.de> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/can/vcan.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -80,7 +80,7 @@ static void vcan_rx(struct sk_buff skb, struct net_device dev)
		skb->dev = dev;
		skb->ip_summed = CHECKSUM_UNNECESSARY;

		netif_rx(skb);
		netif_rx_ni(skb);
		}

		static netdev_tx_t vcan_tx(struct sk_buff skb, struct net_device dev)

net/can/af_can.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -199,6 +199,8 @@ static int can_create(struct net net, struct socket sock, int protocol)
		* @skb: pointer to socket buffer with CAN frame in data section
		* @loop: loopback for listeners on local CAN sockets (recommended default!)
		*
		* Due to the loopback this routine must not be called from hardirq context.
		*
		* Return:
		* 0 on success
		* -ENETDOWN when the selected interface is down
		@@ -278,7 +280,7 @@ int can_send(struct sk_buff *skb, int loop)
		}

		if (newskb)
		netif_rx(newskb);
		netif_rx_ni(newskb);

		/* update statistics */
		can_stats.tx_frames++;

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