[dpdk-dev] [PATCH RFC v3 1/3] vhost: use SMP barriers instead of compiler ones.

[Xie, Huawei]

On 3/18/2016 6:23 PM, Ilya Maximets wrote:
> On 18.03.2016 13:08, Xie, Huawei wrote:
>> On 2/24/2016 7:47 PM, Ilya Maximets wrote:
>>>  		 * Wait until it's our turn to add our buffer
>>> @@ -979,7 +979,7 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
>>>  		entry_success++;
>>>  	}
>>>  
>>> -	rte_compiler_barrier();
>>> +	rte_smp_rmb();
>> smp_rmb()?
> There is no such function 'smp_rmb' in DPDK.
> But:
> .../arch/arm/rte_atomic.h:#define rte_smp_rmb() rte_rmb()
> .../arch/ppc_64/rte_atomic.h:#define rte_smp_rmb() rte_compiler_barrier()
> .../arch/tile/rte_atomic.h:#define rte_smp_rmb() rte_compiler_barrier()
> .../arch/x86/rte_atomic.h:#define rte_smp_rmb() rte_compiler_barrier()

I mean shoudn't be rte_smp_wmb()?

>
>>>  	vq->used->idx += entry_success;
>>>  	vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
>>>  			sizeof(vq->used->idx));
>>> -- 2.5.0
>>
>>