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

From: Kay Sievers
Date: Thu Feb 19 2009 - 06:41:24 EST


On Thu, Feb 19, 2009 at 12:15, Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:
> On Thursday 19 February 2009 00:27:58 Kay Sievers wrote:
>> some modules wait for 200-500 milliseconds to
>> get the lock released, some larger modules spend 50 milliseconds in
>> load_module(), many of them around 20 milliseconds.
>
> OK, this is an untested hack (don't try unloading modules, not sure symbol
> resolution isn't racy now I've killed the lock). Does it change the numbers?

That changes it dramatically. The numbers from the sycall until the
linked-in module are now down to 15-25 milliseconds, and for a few
large modules 50-100.

(One crazy exception is ipv6, which takes 620 milliseconds to link, no
idea what it needs to do.)

I'll compare a few bootup times with and without the patch, and come
back later today with the real numbers.

Thanks a lot,
Kay
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