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Date: Mon, 22 Feb 2010 14:56:46 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Ari Entlich <atrigent@ccs.neu.edu>
Cc: linux-kernel@vger.kernel.org,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH v2] Add a new VT mode which is like VT_PROCESS but
 doesn't require a VT_RELDISP ioctl call
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On Fri, 19 Feb 2010 09:37:55 -0500 (EST) Ari Entlich <atrigent@ccs.neu.edu> wrote:

> This new VT mode (VT_PROCESS_AUTO) does everything that VT_PROCESS does
> except that it doesn't wait for a VT_RELDISP ioctl before switching
> away from a VT with that mode.
> 
> If the X server eventually uses this new mode, debugging and crash
> recovery should become easier. This is because even when currently in
> the VT of a frozen X server it would still be possible to switch out
> by doing SysRq-r and then CTRL-<number of a text vt>, sshing in and
> doing chvt <number of a text vt>, or any other method of VT switching.
> The general concensus on #xorg-devel seems to be that it should be
> safe to use this with X now that we have KMS.

Well, it "should" become easier, but does it?  Has anyone patched their
X server to confirm that this kernel change improves things?  I'm
wondering how this change was tested?

Is there a plan to get the X server modified to use VT_PROCESS_AUTO?

> This also moves the VT_ACKACQ define to a more appropriate place,
> for clarity's sake.
>