ctrl-alt-backspace aka don't zap via GUI, was: Re: [Merge] lp:~albertomilone/gnome-control-center/randr-virtual into lp:~ubuntu-core-dev/gnome-control-center/ubuntu

Timo Aaltonen tjaalton at cc.hut.fi
Fri Jan 30 23:28:52 GMT 2009

On Fri, 30 Jan 2009, Steve Langasek wrote:

> On Fri, Jan 30, 2009 at 04:06:16PM -0500, Scott Kitterman wrote:
>> In that discusion it was declared that alt-sysreq-k was "better" because
>> it's harder to hit accidentally and more reliable due to being implemented
>> in the kernel and not X.
>> So far I've tested this approach on one laptop and I find it "not working".
>>  If we are going to hand this to end users as the solution to a locked X, I
>> think it needs testing first.
> I've tested it here (in response to this discussion) and it "works" in that
> it reliably kills X and gdm respawns it automatically, but it also mangles
> my text VTs.
> Timo says this is a bug in the intel drm driver.  That's fair; but it
> doesn't invalidate the point that using SysReq+K on my system gives inferior
> results compared with Ctrl+Alt+BkSp in the general case.

Actually, upstream said it's more like a feature of the userspace drivers. 
Zap does a leavevt where sysrq+k doesn't, so the hw can be left in an 
inconsistent state, just like when the xserver crashes hard (where zapping 
has been used the most, if it works).

And when the hw supports kernel modesetting there won't be corrupt vt's 


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