On Wed, Apr 02, 2008 at 05:05:09AM +0200, Dennis Jacobfeuerborn wrote:
Harald Hoyer wrote:
Dennis Jacobfeuerborn wrote:
Harald Hoyer wrote:
Compiling these modules, which are loaded on nearly every PC, in the kernel cuts down my boot time from 42s to 32s on my computer:
ata_generic ata_piix
...
sr_mod uhci_hcd
Does the boot time decrease depending on the number of modules you include in the kernel? Maybe it's just one or a few modules that make up the bulk of that time.
to be tested. was just a rough guess of the most common modules, compiled and measured.
Also should configuring these bits as external modules really have this much of an impact on the boot time?
yep. nash, udev, rc.sysinit.. all wait on module loading
But 10s or 25% of boot time just for loading the modules? That sounds quite bad. Maybe instead of moving the modules into the kernel it would be better to find out why exactly the loading takes so long and to look at possible optimizations.
Almost certainly a lot of it will be spent in parsing /lib/modules/$ver/modules.dep Will Cohen did some experiments by sorting that file so that all the modules that he had loaded were at the top of the file. I forget the exact numbers, but it made a noticable difference.
I suspect that if modules.dep was sorted and indexed, that lookups could be made a lot faster than they are now.
Dave