Switching from X-Window to VT

[John Tapsell]

2009/1/13 sdrb <sdrb at onet.eu>:
> John Tapsell wrote:
>>
>> 2009/1/13 sdrb <sdrb at onet.eu>:
>>>
>>> Hi,
>>>
>>> I have a question regarding switching from X-Window to virtual terminal.
>>> Usually I use both of them and I very often switch between of them.
>>> The switching process usually takes 3-8 seconds (X11 -> VT).
>>>
>>> I have Intel E8400 processor and GF7600GT and I wonder why does the
>>> switching from X11 to VT take so much time, while switching in opposite
>>> direction is done almost immediately.
>>> The switching time even grows when I have firefox running with many of
>>> tabs.
>>> Could anyone explain what's going on?
>>
>> Because xorg has drivers for setting up the video card, and so does
>> the kernel. So switching to a VT requires un-setting up the video card
>> by Xorg, then setting up the video card by the kernel.
>>
>> You'll be happy to know, however, that this will hopefully soon(ish)
>> be fixed.  The idea is to move all of this to the kernel.
>> The first steps have already been done  ( 2.6.28 kernel, out on
>> christmas day, came with GEM -
>>
>> http://kernelnewbies.org/Linux_2_6_28#head-b957b19f6139b6bbbfabaf790bf643b1746985d6
>> )
>
> Yes, I heard about GEM, but I'm very interested in what cause this effect.
> Is it possible to read more details (even low-level details) about this
> problem?
If you google for "kernel mode setting" you'll get dozens of hits.  In
particular it's worth checking out the kerneltrap articles (those are
always good - http://kerneltrap.org/node/8242).

>
> Thank you rapid answer.
>
> sdrb
>