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

[Kay Sievers]

On Mon, Mar 2, 2009 at 17:20, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
>> 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....

The "fastboot" kernel commandline option was used, as mentioned in the
mail. Is there anything else?

Thanks,
Kay
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