Re: [Qemu-devel] [PATCH v2 10/12] tcg/tci: Add support for fence

[Sergey Fedorov]

On 27/05/16 17:17, Pranith Kumar wrote:
> Hi Sergey,
>
> Sergey Fedorov writes:
>
>> On 27/05/16 04:00, Richard Henderson wrote:
>>> diff --git a/tci.c b/tci.c
>>> index b488c0d..53b3f71 100644
>>> --- a/tci.c
>>> +++ b/tci.c
>>> @@ -1236,6 +1236,9 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t 
>>> *tb_ptr)
>>>                  tcg_abort();
>>>              }
>>>              break;
>>> +        case INDEX_op_fence:
>>> +            smp_mb();
>>> +            break;
>>>          default:
>>>              TODO();
>>>              break;
>> A bit of bike-shedding. While there's no common ISA term for "memory
>> barrier" (also known as a "membar", "memory fence", etc.), we already
>> refer to it as a "memory barrier" (or "mb") in include/qemu/atomic.h and
>> docs/atomics.txt. Why don't be consistent and avoid introducing yet
>> another term for the same thing?
>>
> Fair point. Do you think tcg_out_mb() is better then?

Yes, if used together with 'INDEX_op_mb', of course.

Kind regards,
Sergey