From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:39720)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1agxf7-0001TK-PX
	for qemu-devel@nongnu.org; Fri, 18 Mar 2016 12:54:10 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1agxf4-0006Wl-ID
	for qemu-devel@nongnu.org; Fri, 18 Mar 2016 12:54:09 -0400
Received: from mx1.redhat.com ([209.132.183.28]:46582)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1agxf4-0006Wh-CR
	for qemu-devel@nongnu.org; Fri, 18 Mar 2016 12:54:06 -0400
References: <1458317932-1875-1-git-send-email-alex.bennee@linaro.org>
	<1458317932-1875-2-git-send-email-alex.bennee@linaro.org>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <56EC32A8.9020903@redhat.com>
Date: Fri, 18 Mar 2016 17:54:00 +0100
MIME-Version: 1.0
In-Reply-To: <1458317932-1875-2-git-send-email-alex.bennee@linaro.org>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Qemu-devel] [RFC v1 01/11] tcg: move tb_find_fast outside the
 tb_lock critical section
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@greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, serge.fdrv@gmail.com, cota@braap.org
Cc: Richard Henderson <rth@twiddle.net>, mark.burton@greensocs.com, qemu-devel@nongnu.org, =?UTF-8?Q?Andreas_F=c3=a4rber?= <afaerber@suse.de>, Peter Crosthwaite <crosthwaite.peter@gmail.com>



On 18/03/2016 17:18, Alex Benn=C3=A9e wrote:
> -#endif
> -
> -    /* if no translated code available, then translate it now */
> -    cpu->tb_invalidated_flag =3D 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 =3D 0;
> +
> +                    /* Clear the flag, we've now observed the flush.  =
*/
> +                    tb_lock_recursive();
> +                    cpu->tb_invalidated_flag =3D 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