Re: [PATCH v2 3/4] mac80211-hwsim: add rate-limited debugging for rx-netlink

[Joe Perches <joe@xxxxxxxxxxx>]

On Mon, 2017-02-27 at 13:56 -0800, greearb@xxxxxxxxxxxxxxx wrote:
> From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
> 
> This makes it easier to understand why wmediumd (or similar)
> is getting errors when sending frames to the kernel.
> 
> Signed-off-by: Ben Greear <greearb@xxxxxxxxxxxxxxx>
> ---
> 
> v2:  Add and use hwsim_ratelimit() instead of net_ratelimit.
>      Squash two patches into this one.
> 
>  drivers/net/wireless/mac80211_hwsim.c | 55 +++++++++++++++++++++++++++--------
>  1 file changed, 43 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
[]
> @@ -137,6 +137,12 @@ static int regtest = HWSIM_REGTEST_DISABLED;
>  module_param(regtest, int, 0444);
>  MODULE_PARM_DESC(regtest, "The type of regulatory test we want to run");
>  
> +DEFINE_RATELIMIT_STATE(hwsim_ratelimit_state, 5 * HZ, 10);
> +int hwsim_ratelimit(void)
> +{
> +	return __ratelimit(&hwsim_ratelimit_state);
> +}

Maybe it'd be better to add a function like

__printf(1, 2)
static void hwsim_dbg_ratelimited(const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (!__ratelimit(&hwsim_ratelimit_state))
		return;

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	printk(KERN_DEBUG "hwsim rx-nl: %pV", &vaf);

	va_end(args);	
}

[]
> @@ -3018,8 +3024,11 @@ static int hwsim_cloned_frame_received_nl(struct sk_buff *skb_2,
>  	if (!info->attrs[HWSIM_ATTR_ADDR_RECEIVER] ||
>  	    !info->attrs[HWSIM_ATTR_FRAME] ||
>  	    !info->attrs[HWSIM_ATTR_RX_RATE] ||
> -	    !info->attrs[HWSIM_ATTR_SIGNAL])
> +	    !info->attrs[HWSIM_ATTR_SIGNAL]) {
> +		if (hwsim_ratelimit())
> +			printk(KERN_DEBUG " hwsim rx-nl: Missing required attribute\n");

so this becomes:

		hwsim_dbg_ratelimited("Missing required attribute\n");

and why are these currently indented with a space?

>  		goto out;
> +	}
>  
>  	dst = (void *)nla_data(info->attrs[HWSIM_ATTR_ADDR_RECEIVER]);
>  	frame_data_len = nla_len(info->attrs[HWSIM_ATTR_FRAME]);
> @@ -3027,29 +3036,53 @@ static int hwsim_cloned_frame_received_nl(struct sk_buff *skb_2,
>  
>  	/* Allocate new skb here */
>  	skb = alloc_skb(frame_data_len, GFP_KERNEL);
> -	if (skb == NULL)
> -		goto err;
> +	if (skb == NULL) {
> +		if (hwsim_ratelimit())
> +			printk(KERN_DEBUG " hwsim rx-nl: skb alloc failed, len: %d\n",
> +			       frame_data_len);

		hwsim_dbg_ratelimited("skb alloc failed, len: %d\n",
				      frame_data_len);

etc...