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

[Sergey Fedorov <serge.fdrv@gmail.com>]

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 :)

>  
>  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);
    }


> +
> +            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(). */


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

Kind regards,
Sergey