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bootchart

Posted: Mon Jul 14, 2008 1:11 pm
by gongo2k1
i've got fedora 9 running on a x41 2526-AD1 (1.5ghz pentium m, 1 gb ram, 60 gb hd, intel 2200bg).

i've disabled a large number of services that i don't need and removed rhgb from my boot parameters, but even so it still takes 58 seconds from grub to gdm login, longer when i'm on battery because of aggressive power settings in the bios.

i installed bootchart and it shows that about half of the boot time is spent on nash-hotplug loading drivers in initrd... is there any way to speed this up?

i realize that the 4200rpm hd is part of what's holding me up, when i boot from my 8gb 266x compactflash the boot time is 45 seconds from power on to usable desktop (that's including the long bios pause for non-ibm hdd, grub, and completing gdm login). both installs are fedora 9 with kernel 2.6.25.9-76.i686.

the problem is, while the cf is MUCH faster, i don't know yet that the increased boot speed is worth the expense.

what are your boot times like?

Posted: Mon Jul 14, 2008 4:26 pm
by aaa
Recompiling the kernel to skip unneeded drivers is how I achieved my fastest boot times. However, it is a bit cumbersome, because whenever I needed a new driver I had to jump through a few hoops to add it. Now I stick with doing it the lengthy default way, mainly because of a faster computer and using standby most of the time.

Also, some people have been outright disabling nash-hotplug. I'm sure this might have some detrimental effect though.

And why not ditch the aggresive bios settings and let the OS take care of power management. Bootup takes alot of power regardless, let the power settings come into effect afterward.

Posted: Mon Jul 14, 2008 9:07 pm
by gongo2k1
well, i can't exactly just disable nash without rebuilding initrd, and if i'm going to do that, i may as well compile the drivers into the kernel as you mentioned. i dunno that 6+ hours effort is worth the couple seconds faster boot up in return. besides, i'd have to do it all over again when there are updates.

i'll try your suggestion about the bios settings though, the more that i think about it, the more it makes sense to just let the boot sequence take as many resources as it needs, it'll boot faster, and then let the os handle power save after that.

i've tried just constantly hibernating, but that takes almost as long as a full boot anyway. well, to be fair, it's slightly faster in that the bios skips post and once the hibernation page loads i don't have to login to gdm.

Posted: Tue Jul 15, 2008 8:57 am
by whizkid
In my experience, suspend to RAM works much better than suspend to disk (hibernate). It's faster too. It does take some power, but a good battery will keep a machine suspended for days.

Posted: Tue Jul 15, 2008 11:51 am
by gongo2k1
i have it set to suspend on lid close but i haven't tried suspending for more than an hour at a time, i always assumed that the power draw wasn't worth it.

then again, given the amount of time it takes to write the hibernation file (even though i've got swap as /dev/sda1, so it's as fast as it can go) and then read it back on startup, the disparity in power usage may not be as great as i think it is.

Posted: Tue Jul 15, 2008 12:17 pm
by aaa
The power usage should be tiny... always more than hibernate, but I haven't lost more than a few percent battery over several hours of standby.

Posted: Tue Jul 15, 2008 2:41 pm
by gongo2k1
k, cool. all of this is good to know. i'm no stranger to laptops, but i've always had larger laptops (two 15.4" and two 14") so they mostly sat on a desk all day. i never really thought about power management because they were always plugged in.