Faster login

[Arturo]

David Zeuthen wrote:

>Hi,
>
>So I had a brief look at shortening startup/login time and tried
>disabling rhgb in favor of starting gdm early. It looks pretty
>promising; here are some wall-clock numbers from two runs of each
>configuration:
>
>                       |   gdm_early  |   rhgb+gdm   |
> ----------------------+------+-------+-------+------+
> GRUB timeout          | 0:00 | 0:00  |  0:00 | 0:00 |
> Starting udev         | 0:13 | 0:13  |  0:13 | 0:14 |
> HW init done          | 0:25 | 0:25  |  0:26 | 0:26 |
> rhgb visible          |  N/A |  N/A  |  0:36 | 0:35 |
> gdm login visible     | 0:43 | 0:44  |  1:25 | 1:26 |
> gdm login entered     | 0:52 | 0:52  |  1:31 | 1:32 |
> GNOME banner visible  | 1:13 | 1:14  |  1:40 | 1:41 |
> Nautilus Background   | 1:33 | 1:32  |  1:51 | 1:52 |
> Panel visible         | 1:43 | 1:43  |  2:02 | 2:02 |
> HD activity off       | 1:59 | 1:56  |  2:13 | 2:14 |
>
>The milestones should be pretty self evident. This is on a stock FC3
>system running on a IBM T41 1.6GHz (running on AC power), 512MB RAM
>without any services manually disabled. 
>
>In addition to starting gdm early, the modifications also start up a few
>services, D-BUS, HAL and NetworkManager, that is critical to the GNOME
>desktop.
>
>Some random thoughts/observations:
>
> - We get the gdm window 40 secs faster 
>
> - The 12 secs from "Starting udev" to "HW init done" can be mostly
>   shaved away/run in parallel
>
> - Kernel bootstrap time (13 secs) can probably be much shorter
>   (that's what some kernel guys say anyway)
>
> - With this hack we shave twenty secs of the booting time (e.g. from
>   GRUB until you can use your PC) but booting still feels much quicker
>   because of the interaction with gdm in the middle (YMMV; e.g. placebo
>   effect etc.)
>
> - rhgb+gdm spawns an X server each which is sort of stupid and unsafe
>   (or so some Xorg guys tell me). This solution, per design, avoids
>   doing that
>
> - we don't get the kudzu screen nor the fsck screens or any other
>   console interactions. However, IMHO, such screens are not good UI
>   in the first place - we should instead have GUI replacemnts that
>   possibly notifies you when you log into the desktop session (stuff
>   like NetworkManager and HAL alleviates such problems for networking
>   and storage devices)
>
> - we don't get service startup notification, but, uhmm, is it really
>   useful learning that the "Console Mouse Service" or "Printing Sub-
>   system" have started? Instead, this stuff could just be put in gdm
>
> - it could be interesting to make /sbin/init own a D-BUS service that
>   gdm and other stuff can query and interact with. Could also be fun
>   to completely replace it with something a'la the SystemServices
>   prototype that Seth did last year; links
>
>   http://www.osnews.com/story.php?news_id=4711
>   http://www.gnome.org/~seth/blog/2003/Sep/27
>
> - Could be interesting to instrument the kernel with some pagefault
>   counters etc. and attempt do more readahead on e.g. the GNOME libs
>   (both Windows XP and Mac OS X does all that; I think we do too but
>   I've been told it can be improved)
>
>So, anyway, I think it could be interesting to discuss starting gdm
>instead of rhgb. If you want to try out my crude hack, grab the file
>here
>
> http://people.redhat.com/davidz/newinit.sh
>
>put it in on your system as /newinit.sh, chmod a+x it and change this
>line /etc/inittab
>
> si::sysinit:/etc/rc.d/rc.sysinit
>
>to these two lines
>
> #si::sysinit:/etc/rc.d/rc.sysinit
> si::sysinit:/newinit.sh
>
>and you should be set to go! If it breaks you get to keep both pieces;
>e.g. try this at your own risk [1].
>
>Cheers,
>David
>
>[1] :if it doesn't work you can boot your kernel with init=/bin/sh, do a
>'mount -n -o remount,rw /' and edit your /etc/inittab file to point to
>the original sysinit.
>
>  
>
You're ideas sound very promising, as I myself have a strong opinion as 
to how things should be, however I do not yet have the expertise to 
implement them myself, and other seem to think such too complicated. 
You're ideas however are a good step. I would just like to raise to issues.

1) I am all for removing outputs of kudzu, fsck and init.d, esp. this 
makes potential convertees somewhat scared to put it one way. However I 
would hope that just as Fedora provides a 'Details' option, a 'Show' 
option should be enabled to allow output from these things.

2) I am all for speeding up the system starup/login (although I have a 
750 Mhz Intel and it really doesn't bother me at all), but would this 
optimization be a Gnome only perk? Or would this be equally or at least 
similiarly beneficial to kdm (KDE).

Thanks