From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:45741) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UdvNR-00087i-0w for qemu-devel@nongnu.org; Sun, 19 May 2013 00:37:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UdvNK-0000Ik-CQ for qemu-devel@nongnu.org; Sun, 19 May 2013 00:37:44 -0400 Received: from mail-ie0-x22f.google.com ([2607:f8b0:4001:c03::22f]:34934) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UdvNK-0000IO-8L for qemu-devel@nongnu.org; Sun, 19 May 2013 00:37:38 -0400 Received: by mail-ie0-f175.google.com with SMTP id s9so11502024iec.6 for ; Sat, 18 May 2013 21:37:37 -0700 (PDT) Date: Sat, 18 May 2013 23:37:33 -0500 From: Rob Landley In-Reply-To: <519667A7.9010902@greensocs.com> (from fred.konrad@greensocs.com on Fri May 17 12:23:51 2013) Message-Id: <1368938253.2611.4@driftwood> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; DelSp=Yes; Format=Flowed Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC] reverse execution. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: KONRAD =?iso-8859-1?b?RnLpZOlyaWM=?= Cc: Blue Swirl , Mark Burton , qemu-devel On 05/17/2013 12:23:51 PM, KONRAD Fr=E9d=E9ric wrote: > On 09/05/2013 19:54, Blue Swirl wrote: >> On Tue, May 7, 2013 at 6:27 PM, KONRAD Fr=E9d=E9ric >> wrote: >>> Hi, >>>=20 >>> We are trying to find a way to do reverse execution happen with =20 >>> QEMU. ... > For now we tried some other things which are not working very well, >=20 > It appeared that the replay is not deterministic even with icount: You're aware that reverse execution means you have the "come from" =20 problem, right? (The opposite of goto.) You literally _can't_ figure out your control flow by running the code =20 backwards. It's equivalent to solving the halting problem. The best you =20 can do is log and replay. Rob=