Re: [Qemu-devel] [RFC v2 07/11] tcg: cpus rm tcg_exec_all()

[Alex Bennée]

Sergey Fedorov <address@hidden> writes:

> On 05/04/16 18:32, Alex Bennée wrote:
>> diff --git a/cpus.c b/cpus.c
>> index e118fdf..46732a5 100644
>> --- a/cpus.c
>> +++ b/cpus.c
> (snip)
>> @@ -1109,7 +1108,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
>>  #endif
>>  }
>>
>> -static void tcg_exec_all(void);
>> +static int tcg_cpu_exec(CPUState *cpu);
>
> Why don't just move tcg_cpu_exec() here and avoid this forward
> declaration. Such forward declarations of static functions are a bit
> annoying :)

Sounds like a plan.

>
>>
>>  static void *qemu_tcg_cpu_thread_fn(void *arg)
>>  {
>> @@ -1140,8 +1139,35 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
>>      /* process any pending work */
>>      atomic_mb_set(&exit_request, 1);
>>
>> +    cpu = first_cpu;
>> +
>>      while (1) {
>> -        tcg_exec_all();
>> +        /* Account partial waits to QEMU_CLOCK_VIRTUAL.  */
>> +        qemu_account_warp_timer();
>> +
>> +        if (!cpu) {
>> +            cpu = first_cpu;
>> +        }
>> +
>> +        for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) {
>
> Maybe a "while" cycle would be a bit neater here, like:
>
>     while (cpu != NULL && !exit_request) {
>         /* ... */
>         cpu = CPU_NEXT(cpu);
>     }

Yeah, I prefer the while to non-standard for loops.

>
>
>> +
>> +            qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
>> +                              (cpu->singlestep_enabled & SSTEP_NOTIMER) == 
>> 0);
>> +
>> +            if (cpu_can_run(cpu)) {
>> +                int r = tcg_cpu_exec(cpu);
>> +                if (r == EXCP_DEBUG) {
>> +                    cpu_handle_guest_debug(cpu);
>> +                    break;
>> +                }
>> +            } else if (cpu->stop || cpu->stopped) {
>> +                break;
>> +            }
>> +
>> +        } /* for cpu.. */
>> +
>> +        /* Pairs with smp_wmb in qemu_cpu_kick.  */
>
> While at it, we could also fix this comment like this:
>
>     /* Pairs with atomic_mb_read() in cpu_exec(). */

Will do.

>
>> +        atomic_mb_set(&exit_request, 0);
>>
>>          if (use_icount) {
>>              int64_t deadline = 
>> qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
>
> Kind regards,
> Sergey

Thanks,


--
Alex Bennée