Re: Test some kernel feature without recompile

[Jesper Juhl]

On Sun, 22 Mar 2009, Dragoslav Zaric wrote:

> Hi,
> 
> I know when you work on some kernel module, you can change code and load
> module again and test it, but what if you change some built in kernel
> .c file, why
> would I need to recompile whole kernel just to see what happens if I change one
> .c file ??
> 
Depends on the nature of the change. Some changes will ripple through the 
whole kernel.
If, for example, you made a change to kmalloc() so that it takes an extra 
argument, then obviously all call sites would need changing and since 
kmalloc is used almose everywhere, then almost all files would need to be 
recompiled.
But if your change is entirely contained to a single file, then 'make' 
will already ensure that only that file is rebuilt when you run 'make' 
(you'll still have to re-link the kernel or module though and a reboot 
will still be needed).

> Why can I just compile one changed .c file and copy it where compiled version of
> that file reside inside kernel tree? 

'make' should already handle that for you. In what way does it not?

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