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From: Pranith Kumar <bobby.prani@gmail.com>
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Date: Fri, 27 May 2016 10:17:17 -0400
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Subject: Re: [Qemu-devel] [PATCH v2 10/12] tcg/tci: Add support for fence
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To: Sergey Fedorov <serge.fdrv@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>, qemu-devel@nongnu.org, Stefan Weil <sw@weilnetz.de>


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?

Thanks,
-- 
Pranith