[dpdk-dev] [PATCH v7 4/8] vhost: rxtx: use queue id instead of constant ring index

[Xie, Huawei]

On 10/21/2015 12:44 PM, Stephen Hemminger wrote:
> On Wed, 21 Oct 2015 11:48:10 +0800
> Yuanhan Liu <yuanhan.liu at linux.intel.com> wrote:
>
>>  
>> +static inline int __attribute__((always_inline))
>> +is_valid_virt_queue_idx(uint32_t virtq_idx, int is_tx, uint32_t max_qp_idx)
>> +{
>> +	if ((is_tx ^ (virtq_idx & 0x1)) ||
>> +	    (virtq_idx >= max_qp_idx * VIRTIO_QNUM))
>> +		return 0;
>> +
>> +	return 1;
>> +}
> minor nits:
>  * this doesn't need to be marked as always inline, 
>     that is as they say in English "shooting a fly with a bazooka"
Stephen:
always_inline "forces" the compiler to inline this function, like a macro.
When should it be used or is it not preferred at all?

>  * prefer to just return logical result rather than have conditional:
>  * for booleans prefer the <stdbool.h> type boolean.
>
> static bool
> is_valid_virt_queue_idx(uint32_t virtq_idx, bool is_tx, uint32_t max_qp_idx)
> {
> 	return (is_tx ^ (virtq_idx & 1)) || 
> 		virtq_idx >= max_qp_idx * VIRTIO_QNUM;
> }
>