Re: [PATCH] netpoll: WARN_ONCE for start_xmit returns with interrupts enabled

[Matt Mackall <mpm@selenic.com>]

On Wed, 2009-08-19 at 18:43 +0800, DDD wrote:
> The NETPOLL API requires that interrupts remain disabled in
> netpoll_send_skb().
> 
> Add a WARN_ONCE when ndo_start_xmit returns with interrupts enabled
> in netpoll_send_skb().
> 
> Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
> ---
>  net/core/netpoll.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/net/core/netpoll.c b/net/core/netpoll.c
> index df30feb..d38103f 100644
> --- a/net/core/netpoll.c
> +++ b/net/core/netpoll.c
> @@ -319,6 +319,12 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
>  
>  			udelay(USEC_PER_POLL);
>  		}
> +
> +		WARN_ONCE(!irqs_disabled(),
> +			KERN_WARNING "netpoll_send_skb(): [net driver %s]"
> +			"ndo_start_xmit() shouldn't return with interrupts"
> +			"enabled!", dev->name);

Hmm, perhaps:

"netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n",
dev->name, ops->ndo_start_xmit

That'll give us a real function name and maybe even a module name.

-- 
http://selenic.com : development and support for Mercurial and Linux