Re: [PATCH v14 04/10] accel/tcg: add jit stats and time to TBStatistics

[Richard Henderson <richard.henderson@linaro.org>]

On 5/31/23 23:48, Wu, Fei wrote:
>>> -int64_t tcg_cpu_exec_time(void);
>>> +uint64_t tcg_cpu_exec_time(void);
>>
>> Why?  (Also, probably wants removing, per above.)
>>
> The original patch mentioned 'make it an uint64_t as we won't be dealing
> in negative numbers.'

The signed vs unsigned thing is something that should be handled throughout everything 
that handles times, not adjusted here and there by only profiling.

>>> --- a/softmmu/runstate.c
>>> +++ b/softmmu/runstate.c
>>> @@ -728,9 +728,18 @@ static bool main_loop_should_exit(int *status)
>>>    int qemu_main_loop(void)
>>>    {
>>>        int status = EXIT_SUCCESS;
>>> +#ifdef CONFIG_TCG
>>> +    uint64_t ti;
>>> +#endif
>>>          while (!main_loop_should_exit(&status)) {
>>> +#ifdef CONFIG_TCG
>>> +        ti = profile_getclock();
>>> +#endif
>>>            main_loop_wait(false);
>>> +#ifdef CONFIG_TCG
>>> +        dev_time += profile_getclock() - ti;
>>> +#endif
>>>        }
>>
>> What is this intending to collect?  Because I don't think it measures
>> anything.  Certainly nothing related to TCG, CPUs or even devices.
>>
> It's exported to hmp cmd in dump_jit_exec_time_info() together with
> cpu_exec_time.

That doesn't answer my question: What do you think it measures?

r~