Re: [RFC PATCH 0/6] module, kbuild: Faster boot with custom kernel.

From: Arjan van de Ven
Date: Mon Mar 02 2009 - 11:19:44 EST


> A monolithic kernel with parallelized initcalls is better - about 200
> ms faster than parallel insmods on my test system. However, it comes
> with a fairly large set of changes:
>
> * First, you need a 200-line patch in init/main.c (do_initcalls() and
> friends)

why?
We already have async function calls; and those speed up my boot (when
enabled) significantly, by doing much of the kernel/driver init in
parallel.

My server box boots the whole kernel (including all drivers; I build
verything in) in 0.56 seconds, and my net books do it in around 1.0
seconds.

>
> * Then the built-in module dependencies must be calculated properly,
> eg with a modified depmod, and added to the build process.

nope not if done right

> So, what do you think, should I keep going? IMHO, the slower userspace
> implementation is acceptable since it's so much simpler.

I would strongly suggest that you turn on the async function calls and
look at the boot graph of the resulting kernel boot... if you send
that to me I can also take a look and make suggestions....

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