Re: [dpdk-dev] [PATCH v2] net/vhost: fix redundant queue state event

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 6/20/19 8:33 AM, Noa Ezra wrote:
> In some situations, when a virtual machine is starting,
> vring_state_changed can be called while there was no change in the
> queue state. This fix makes sure that there was really a change in the
> queue state before calling the callback for EVENT_QUEUE_STATE.
> 
> Fixes: ee584e9710b9 ("vhost: add driver on top of the library")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Noa Ezra <noae@mellanox.com>
> Reviewed-by: Matan Azrad <matan@mellanox.com>
> ---
> v2 remove checkpatch warnings
> ---
>  drivers/net/vhost/rte_eth_vhost.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
> index cad1e5c..fbe7a37 100644
> --- a/drivers/net/vhost/rte_eth_vhost.c
> +++ b/drivers/net/vhost/rte_eth_vhost.c
> @@ -855,6 +855,10 @@ struct vhost_xstats_name_off {
>  	/* won't be NULL */
>  	state = vring_states[eth_dev->data->port_id];
>  	rte_spinlock_lock(&state->lock);
> +	if (state->cur[vring] == enable) {
> +		rte_spinlock_unlock(&state->lock);
> +		return 0;
> +	}
>  
>  	state->cur[vring] = enable;
>  	state->max_vring = RTE_MAX(vring, state->max_vring);
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime