Re: [PATCH] replay: don't wait in run_on_cpu

[Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>]

On 29.03.2021 12:42, Paolo Bonzini wrote:
> On 29/03/21 10:05, Pavel Dovgalyuk wrote:
>> @@ -136,7 +137,13 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func 
>> func, run_on_cpu_data data,
>>   {
>>       struct qemu_work_item wi;
>> -    if (qemu_cpu_is_self(cpu)) {
>> +    if (qemu_cpu_is_self(cpu)
>> +        /*
>> +         * vCPU thread is waiting when replay mutex is locked
>> +         * and the task is not exclusive, the function may be called
>> +         * without other synchronization.
>> +         */
>> +        || (replay_mode != REPLAY_MODE_NONE && replay_mutex_locked())) {
>>           func(cpu, data);
>>           return;
>>       }
> 
> Is the "or" saying that the execution is using the lockstep mode?  If 
> so, can you put it in a separate function so that it's more 
> self-explanatory and check if it should be used elsewhere?

It was replay (is that lockstep that you mentioned?).
I check that the mutex is already locked, which means, that vCPU
does nothing at this moment.

Pavel Dovgalyuk