Re: [dpdk-stable] [dpdk-dev] [PATCH] examples/kni: fix crash during MTU set

[Thomas Monjalon <thomas@monjalon.net>]

21/05/2020 17:10, Ferruh Yigit:
> During MTU set (kni_change_mtu) sample application setup queues, which
> can free and re-allocate queues.
> Meanwhile sample application keeps continues in Rx/Tx burst calls in
> different threads, which may cause crash during queue setup.
> 
> Pausing application Rx/Tx calls before MTU set and starts it back
> afterwards.
> 
> Bugzilla ID: 482
> Fixes: a26b116749a3 ("examples/kni: fix MTU change to setup Tx queue")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> ---
> -/* Callback for request of changing MTU */
>  static int
> -kni_change_mtu(uint16_t port_id, unsigned int new_mtu)
> +kni_change_mtu_(uint16_t port_id, unsigned int new_mtu)
[...]
> +/* Callback for request of changing MTU */
> +static int
> +kni_change_mtu(uint16_t port_id, unsigned int new_mtu)
> +{
> +	int ret;
> +
> +	rte_atomic32_inc(&kni_pause);
> +	ret =  kni_change_mtu_(port_id, new_mtu);
> +	rte_atomic32_dec(&kni_pause);
> +
> +	return ret;
> +}

Why creating a new function which is called only once?