From: "H. Peter Anvin" <hpa@zytor.com>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Pavel Emelyanov <xemul@parallels.com>,
Jiri Slaby <jslaby@suse.cz>
Subject: Re: [RFC] tty: Add get- ioctls to fetch tty status
Date: Thu, 27 Sep 2012 07:43:44 -0700 [thread overview]
Message-ID: <50646620.4090708@zytor.com> (raw)
In-Reply-To: <20120927142149.GH6618@moon>
On 09/27/2012 07:21 AM, Cyrill Gorcunov wrote:
> On Thu, Sep 27, 2012 at 07:17:49AM -0700, H. Peter Anvin wrote:
>>> While we easily can fetch termios settings and such, there are few bits which
>>> are missed to expord. So this patch provides them to user-space.
>>>
>>
>> What bothers me (and the same applies to termios) is that you have
>> NO idea if your particular process is the "owner" of that tty. tty
>> users use out-of-band protocols, often implicit, to determine which
>> process "owns" the tty state.
>>
>> If you can't guarantee that ALL those processes are stopped and
>> checkpointed/restarted, you have a huge problem.
>
> Well, sure inside our tool before doing checkpoint we stop all
> tasks which are part of dumpee process tree. This unfortunatly
> doesn't apply to these ioctl calls. Peter, any idea how to deal
> with that?
>
Sorry, no. I suspect you might be trying to do something that is
impossible to do in a general fashion without application changes.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2012-09-27 14:44 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 9:56 [RFC] tty: Add get- ioctls to fetch tty status Cyrill Gorcunov
2012-09-13 11:46 ` Jiri Slaby
2012-09-13 11:51 ` Cyrill Gorcunov
2012-09-13 12:51 ` Alan Cox
2012-09-13 12:54 ` Cyrill Gorcunov
2012-09-13 16:25 ` Alan Cox
2012-09-13 16:41 ` Cyrill Gorcunov
2012-09-22 18:06 ` Cyrill Gorcunov
2012-09-22 20:07 ` Greg Kroah-Hartman
2012-09-22 20:11 ` Cyrill Gorcunov
2012-09-22 21:52 ` Cyrill Gorcunov
2012-09-23 1:09 ` Greg Kroah-Hartman
2012-09-23 6:40 ` Cyrill Gorcunov
2012-09-23 14:46 ` H. Peter Anvin
2012-09-23 15:21 ` Cyrill Gorcunov
2012-09-24 14:14 ` Cyrill Gorcunov
2012-09-27 14:05 ` Cyrill Gorcunov
2012-09-27 14:14 ` Alan Cox
2012-09-27 14:14 ` Cyrill Gorcunov
2012-09-27 14:17 ` H. Peter Anvin
2012-09-27 14:21 ` Cyrill Gorcunov
2012-09-27 14:43 ` H. Peter Anvin [this message]
2012-09-27 14:48 ` Cyrill Gorcunov
2012-09-27 15:05 ` H. Peter Anvin
2012-09-27 15:13 ` Alan Cox
2012-09-27 15:23 ` Cyrill Gorcunov
2012-09-27 16:00 ` Alan Cox
2012-09-27 16:06 ` Cyrill Gorcunov
2012-09-27 15:47 ` Cyrill Gorcunov
2012-09-22 23:15 ` Alan Cox
2012-09-23 1:43 ` Eric W. Biederman
2012-09-23 6:40 ` Cyrill Gorcunov
2012-09-23 14:44 ` H. Peter Anvin
2012-09-23 15:22 ` Cyrill Gorcunov
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