Re: [Qemu-devel] [PATCH 02/10] tcg: Pass last_tb by value to tb_find_fast()

["Alex Bennée" <alex.bennee@linaro.org>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> From: Sergey Fedorov <serge.fdrv@gmail.com>
>
> This is a small clean up. tb_find_fast() is a final consumer of this
> variable so no need to pass it by reference. 'last_tb' is always updated
> by subsequent cpu_loop_exec_tb() in cpu_exec().
>
<snip>
> @@ -621,7 +620,7 @@ int cpu_exec(CPUState *cpu)
>              cpu->tb_flushed = false; /* reset before first TB lookup */
>              for(;;) {
>                  cpu_handle_interrupt(cpu, &last_tb);
> -                tb = tb_find_fast(cpu, &last_tb, tb_exit);
> +                tb = tb_find_fast(cpu, last_tb, tb_exit);

Maybe a comment here for those that missed the subtly in the commit
message?

                   /* cpu_loop_exec_tb updates a to a new last_tb */

>                  cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);

You could even make it explicit and change cpu_loop_exec_tb to return
last_tb instead of passing by reference. Then it would be even clearer
when reading the code.

>                  /* Try to align the host and virtual clocks
>                     if the guest is in advance */



--
Alex Bennée