Re: [PATCH v13 04/10] accel/tcg: add jit stats and time to TBStatistics

[Wu, Fei]

On 6/1/2023 7:51 PM, Alex Bennée wrote:
> 
> "Wu, Fei" <fei2.wu@intel.com> writes:
> 
>> On 5/30/2023 6:08 PM, Alex Bennée wrote:
>>>
>>> "Wu, Fei" <fei2.wu@intel.com> writes:
>>>
>>>> On 5/30/2023 1:01 PM, Wu, Fei wrote:
>>>>> On 5/30/2023 12:07 PM, Richard Henderson wrote:
>>>>>> On 5/29/23 04:49, Fei Wu wrote:
> <snip>
>> ----------------
>> IN:
>> Priv: 1; Virt: 0
>>
>> 0xffffffff800abe14:  864a              mv                      a2,s2
>> 0xffffffff800abe16:  85ce              mv                      a1,s3
>> 0xffffffff800abe18:  8526              mv                      a0,s1
>> 0xffffffff800abe1a:  46bd              addi                    a3,zero,15
>> 0xffffffff800abe1c:  fffff097          auipc                   ra,-4096
>>               # 0xffffffff800aae1c
>> 0xffffffff800abe20:  cc0080e7          jalr                    ra,ra,-832
>> ------------------------------
>>
>> Look at the tb with phys:0x2abe14, although the first time IR takes
>> 75274ns, but in the second command we can see it takes much less time
>> (Note IR time is accumulated).
>>
>> So if the time for the same TB is not consistent, and the deviation
>> could be dominated by system events such as memory allocation instead of
>> codegen itself (?), I think it's less useful.
>>
>> Alex, regarding dropping time profile, do you mean remove TB_JIT_TIME
>> completely?
> 
> I think so - perf would do a better job of separating system events from
> the core code as it has better visibility of the whole system. 
> 
OK, got it.

Richard, can we reach the agreement here? If yes, I will remove
TB_JIT_TIME and all the time stuffs (dev_time, cpu_exec_time)
completely. We can still add it back if it proves to be useful. The only
concern is that tbstats replaces CONFIG_PROFILER but drops this function
from it.

Thanks,
Fei.