[dpdk-dev] [PATCH v7 09/15] vhost: add shadow used ring support for packed rings

[Maxime Coquelin]

On 07/05/2018 04:03 PM, Tiwei Bie wrote:
> On Thu, Jul 05, 2018 at 02:49:34PM +0200, Maxime Coquelin wrote:
>> On 07/05/2018 09:15 AM, Tiwei Bie wrote:
>>> On Wed, Jul 04, 2018 at 11:54:32PM +0200, Maxime Coquelin wrote:
>>> [...]
>>>> +
>>>> +static __rte_always_inline void
>>>> +flush_shadow_used_ring_packed(struct virtio_net *dev,
>>>> +			struct vhost_virtqueue *vq)
>>>> +{
>>> [...]
>>>> +}
>>>> +
>>>> +static __rte_always_inline void
>>>> +update_shadow_used_ring_packed(struct vhost_virtqueue *vq,
>>>> +			 uint16_t desc_idx, uint16_t len, uint16_t count)
>>>> +{
>>>> +	uint16_t i = vq->shadow_used_idx++;
>>>> +
>>>> +	vq->shadow_used_packed[i].id  = desc_idx;
>>>> +	vq->shadow_used_packed[i].len = len;
>>>> +	vq->shadow_used_packed[i].count = count;
>>>>    }
>>>
>>> I met below build errors in this patch when doing
>>> per-patch build test with clang:
>>>
>>> lib/librte_vhost/virtio_net.c:134:1: error: unused function 'flush_shadow_used_ring_packed'
>>>         [-Werror,-Wunused-function]
>>> flush_shadow_used_ring_packed(struct virtio_net *dev,
>>> ^
>>> lib/librte_vhost/virtio_net.c:188:1: error: unused function 'update_shadow_used_ring_packed'
>>>         [-Werror,-Wunused-function]
>>> update_shadow_used_ring_packed(struct vhost_virtqueue *vq,
>>> ^
>>>
>>> It's better to add __rte_unused in this patch,
>>> and remove it when functions are used.
>>>
>>> PS. I also saw similar errors with fill_vec_buf_packed()
>>>       in patch 11/15.
>>>
>>
>> Thanks for the report, I missed these build issues...
>> This is not fixed using __rte_unused as you suggested.
>>
Oops, I meant "This *now* fixed using __rte_unused" :)

> 
> Why not? This can be fixed by something like this
> on my machine:
> 
> -static __rte_always_inline void
> +static __rte_always_inline __rte_unused void
>   flush_shadow_used_ring_packed(struct virtio_net *dev,
>   			struct vhost_virtqueue *vq)
>   {
> 
> And __rte_unused can be removed in the patch that
> above function is called.
> 
> Best regards,
> Tiwei Bie
>