From: Peter Maydell <peter.maydell@linaro.org>
To: Rob Landley <rob@landley.net>
Cc: "Blue Swirl" <blauwirbel@gmail.com>,
"Mark Burton" <mark.burton@greensocs.com>,
qemu-devel <qemu-devel@nongnu.org>,
"KONRAD Frédéric" <fred.konrad@greensocs.com>
Subject: Re: [Qemu-devel] [RFC] reverse execution.
Date: Sun, 19 May 2013 08:21:38 +0100 [thread overview]
Message-ID: <CAFEAcA_UhsmMiKER1gWhWJ-R5abpege_9XZUn7xV+pOU62LBEA@mail.gmail.com> (raw)
In-Reply-To: <1368938253.2611.4@driftwood>
On 19 May 2013 05:37, Rob Landley <rob@landley.net> wrote:
> On 05/17/2013 12:23:51 PM, KONRAD Frédéric wrote:
>> It appeared that the replay is not deterministic even with icount:
> You're aware that reverse execution means you have the "come from" problem,
> right? (The opposite of goto.)
>
> You literally _can't_ figure out your control flow by running the code
> backwards. It's equivalent to solving the halting problem. The best you can
> do is log and replay.
Yes, of course -- 'reverse execution' is just the usual phrase
for the user-visible effect. However if your *forwards* replay
isn't deterministic then it all goes pear-shaped, which is
what Fred is complaining about.
-- PMM
next prev parent reply other threads:[~2013-05-19 7:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-07 18:27 [Qemu-devel] [RFC] reverse execution KONRAD Frédéric
2013-05-09 17:54 ` Blue Swirl
2013-05-17 17:23 ` KONRAD Frédéric
2013-05-17 17:54 ` Peter Maydell
2013-05-17 19:16 ` Mark Burton
2013-05-23 1:57 ` Edgar E. Iglesias
2013-05-18 18:52 ` Blue Swirl
2013-05-22 16:14 ` KONRAD Frédéric
2013-05-19 4:37 ` Rob Landley
2013-05-19 7:21 ` Peter Maydell [this message]
2013-05-19 20:09 ` Mark Burton
2013-05-19 21:20 ` Peter Maydell
[not found] ` <CAD2=zRDphd7N5gCQeX6oVQP=HEbRRMpcwPKEVDj46DHKhgkKMw@mail.gmail.com>
2013-05-19 21:47 ` Brendan Dolan-Gavitt
2013-05-20 5:28 ` Mark Burton
2013-05-19 21:39 ` Rob Landley
2013-05-20 5:34 ` Mark Burton
2013-05-29 12:37 ` Pavel Dovgaluk
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