Re: [gentoo-user] new machine : start-up time

[Canek Peláez Valdés]

On Sat, Oct 13, 2012 at 5:28 PM, Volker Armin Hemmann
<volkerarmin@××××××××××.com> wrote:
> Am Samstag, 13. Oktober 2012, 16:40:45 schrieb Canek Peláez Valdés:
>> On Sat, Oct 13, 2012 at 4:14 PM, Volker Armin Hemmann
>>
>> <volkerarmin@××××××××××.com> wrote:
>> > Am Samstag, 13. Oktober 2012, 15:57:31 schrieb Canek Peláez Valdés:
>> >> On Sat, Oct 13, 2012 at 3:40 PM, Canek Peláez Valdés <caneko@×××××.com>
>> >
>> > wrote:
>> >> > On Sat, Oct 13, 2012 at 3:24 PM, Philip Webb <purslow@××××××××.net>
> wrote:
>> >> >> Regulars will remember the threads re the machine I built recently.
>> >> >> I thought they mb interested in the start-up time now all is working :
>> >> >> Gigabyte BIOS  10 s , Linux Lilo prompt - login prompt  8 s ,
>> >> >> 'startx' - GUI ready  4 s : total  22 s  + entering userid+password ;
>> >> >> I start the I/net connection (Dhcpcd) manually from the GUI ( 15 s ).
>> >> >> I assume most of the speed is attributable to the SSD,
>> >> >> perhaps a bit to the 1600 MHz memory; of course, Gentoo shares the
>> >> >> honors;
>> >> >> my desktop manager is Fluxbox & I start apps on desktops manually.
>> >> >
>> >> > Toshiba Portégé Z830, with an iCore 5 at 1.60GHz, 6 GB of memory, and
>> >> > a tiny 128 GB SSD. It takes 12 seconds from GRUB to GDM, and from the
>> >> > time I enter my password and my GNOME 3 desktop is ready it takes
>> >> > another 6 seconds, so 18 seconds in total (plus how much it takes for
>> >> > me to click in my user and enter my password).
>> >> >
>> >> > Like you, I attribute most of the speed gain to the SSD. The rest is
>> >> > systemd.
>> >>
>> >> Damn, is GNOME fat. I booted to text console (disabled GDM), and I
>> >> also disabled plymouth. From GRUB2 to login prompt it takes less than
>> >> 6 seconds, so the really slow part is starting GDM and then switching
>> >> to GNOME 3. The BIOS is pretty fast, it takes 4 seconds from power on
>> >> to the GRUB2 menu.
>> >>
>> >> The fast part (GRUB2->login prompt) is because of systemd.
>> >
>> > I doubt that,
>>
>> Install systemd and do the test; I got the numbers to prove it.
>> systemd is consistently faster than OpenRC (which doesn't even
>> properly  support parallel starting of services), sometimes several
>> times faster.
>>
>> Luca Barbato mentioned about a way to make OpenRC use busybox in
>> reentrant mode; the difference in speed in that case should be less.
>> However, the fact is that OpenRC doesn't support parallel start of
>> services; it said so in its own documentation:
>>
>> https://bugs.gentoo.org/show_bug.cgi?id=391945#c10
>>
>> "rc_parallel has never officially been declared a stable feature (see
>> the comments in rc.conf regarding this)."
>>
>> So no matter how fast the scripts could execute (which anyway will be
>> slower than small highly optimized C programs), the lack of proper
>> parallelization will make OpenRC slower than systemd.
>>
>> So doubt as much as you want. It doesn't change the fact that (in this
>> particular issue), you are wrong.
>>
>
> and since I use openrc with parallel startup, I just doubt it even more.

So you know better than the devs. I'm sure you believe so; good luck with that.

I would do the test, though; otherwise you are talking about beliefs, not facts.

> The place where I lose time is starting of my five md-raids. And that is
> something not even systemd can speed up.

That may be true, but until someone does the benchmark we don't know.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México