| Date | Thu, 01 Oct 2009 18:16:56 -0700 | From | Greg KH <> | Subject | [068/136] can: fix NOHZ local_softirq_pending 08 warning |
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2.6.31-stable review patch. If anyone has any objections, please let us know.
------------------ From: Oliver Hartkopp <oliver@hartkopp.net>
commit 481a8199142c050b72bff8a1956a49fd0a75bbe0 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/net/can/vcan.c | 2 +- net/can/af_can.c | 4 +++- 2 files changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/net/can/vcan.c +++ b/drivers/net/can/vcan.c @@ -80,7 +80,7 @@ static void vcan_rx(struct sk_buff *skb, skb->dev = dev; skb->ip_summed = CHECKSUM_UNNECESSARY; - netif_rx(skb); + netif_rx_ni(skb); } static int vcan_tx(struct sk_buff *skb, struct net_device *dev) --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -199,6 +199,8 @@ static int can_create(struct net *net, s * @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 lo } if (newskb) - netif_rx(newskb); + netif_rx_ni(newskb); /* update statistics */ can_stats.tx_frames++;
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