From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:56280)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1b5t59-00072O-Hl
	for qemu-devel@nongnu.org; Thu, 26 May 2016 07:04:09 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1b5t55-0002xD-B9
	for qemu-devel@nongnu.org; Thu, 26 May 2016 07:04:02 -0400
Received: from mail-lf0-x241.google.com ([2a00:1450:4010:c07::241]:34914)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1b5t54-0002wt-UP
	for qemu-devel@nongnu.org; Thu, 26 May 2016 07:03:59 -0400
Received: by mail-lf0-x241.google.com with SMTP id p10so5687214lfb.2
	for <qemu-devel@nongnu.org>; Thu, 26 May 2016 04:03:58 -0700 (PDT)
References: <1459870344-16773-1-git-send-email-alex.bennee@linaro.org>
	<1459870344-16773-8-git-send-email-alex.bennee@linaro.org>
From: Sergey Fedorov <serge.fdrv@gmail.com>
Message-ID: <5746D81C.8030506@gmail.com>
Date: Thu, 26 May 2016 14:03:56 +0300
MIME-Version: 1.0
In-Reply-To: <1459870344-16773-8-git-send-email-alex.bennee@linaro.org>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Subject: Re: [Qemu-devel] [RFC v2 07/11] tcg: cpus rm tcg_exec_all()
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>, mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, cota@braap.org
Cc: qemu-devel@nongnu.org, mark.burton@greensocs.com, pbonzini@redhat.com, jan.kiszka@siemens.com, rth@twiddle.net, peter.maydell@linaro.org, claudio.fontana@huawei.com, Peter Crosthwaite <crosthwaite.peter@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