Re: [Cooker] ANNOUNCE : Speedboot, phase 1, has landed on cooker

[Gustavo De Nardin (spuk)]

* Frederic Crozat <fcrozat@mandriva.com> [2009-02-05 20:44 +0100]:
> Hi everybody,
> 
> just in time for beta 1 of 2009 Spring, I've finished pushing support
> for phase 1 of speedboot feature.
> 
> What do speedboot :
> Speedboot is trying to start first all needed actions for the graphical
> system (display manager) to be able to start and then, continue all
> other actions needed for a full boot, in background.
> 
> How is it implemented ?
> We are reusing techniques which have been used already on some of our
> OEM products, with finit, but with more standard implementation, keeping
> current initscripts.
> 
> To be able to start minimal services needed for display manager to
> start, we introduced S runlevel (with only 5 services : acpid, dbus,
> hal, syslog and dm). Unfortunately chkconfig code only likes numeric
> runlevels, so runlevel S is implemented as runlevel 7 (both represent
> the same runlevel, but 7 is the one to be used in initscripts).

Why reuse 'S' instead of just going with 7?:
~ # grep -B1 -w S /etc/inittab
# Single user mode
~~:S:wait:/bin/sh


> When booting in speedboot mode, a lot of actions which were done in
> initscripts are ignored. This is why speedboot might not work on your
> system. 
> 
> For phase 1 of speedboot, I disabled as much actions as possible in
> rc.sysinit. Some actions just need to be delayed after display manager
> is started, so I'll try to defer some of the currently disabled actions,
> for phase 2 of speedboot.
> 
> In phase 2 (or 3) of speedboot, we will automatically enable speedboot
> if some criteras are met and if no conflicting features are enabled on
> the system, such as crypto FS, raid, network authentication. If
> speedboot fails, the system will automatically fallback to standard boot
> and will not retry speedboot by itself.
> 
> Currently, readahead has been completely disabled when using speedboot.
> Our measures showed regressions when using either readahead or
> sreadahead but they were not done on SSD drives.
> 
> How can I use speedboot ?
> 
> By default for beta 1, speedboot is DISABLED. If you want to enabled
> speedboot, add speedboot keyword to your kernel commandline and reboot.
> 
> Of course, we would like to collect as much bootchart data as possible,
> both when speedboot is enabled and when it is not.
> 
> If speedboot is failing on your system, we are interested too.
> 
> Enjoy
> 
> -- 
> Frederic Crozat <fcrozat@mandriva.com>
> Mandriva
> 

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