Re: [Qemu-devel] [RFC v1 01/11] tcg: move tb_find_fast outside the tb_lock critical section

[Paolo Bonzini]

On 18/03/2016 17:18, Alex Bennée wrote:
> -#endif
> -
> -    /* if no translated code available, then translate it now */
> -    cpu->tb_invalidated_flag = 0;

Moving this reset from here...

> -                if (cpu->tb_invalidated_flag) {
> +                if (atomic_read(&cpu->tb_invalidated_flag)) {
>                      /* as some TB could have been invalidated because
>                         of a tb_flush while generating the code, we
>                         must recompute the hash index here */
>                      next_tb = 0;
> +
> +                    /* Clear the flag, we've now observed the flush.  */
> +                    tb_lock_recursive();
> +                    cpu->tb_invalidated_flag = 0;
>                  }

... to here probably can be anticipated to Sergey's (my? :D) "make
tb_invalidated_flag per-CPU" patch.

Then this patch can just add the tb_lock_recursive.

Paolo