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From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org>
To: Pratik Singhal <ps06756@gmail.com>
Subject: Re: Compilation taking too long time
References: <CAGf2gkNHdoYv=_QgSMZF0gjHTcXJKJvAy69=HKPU=NgbCsT6ug@mail.gmail.com>
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Date: Thu, 09 Apr 2015 19:13:23 -0400
In-Reply-To: <CAGf2gkNHdoYv=_QgSMZF0gjHTcXJKJvAy69=HKPU=NgbCsT6ug@mail.gmail.com>
 (Pratik Singhal's message of "Fri, 10 Apr 2015 01:08:25 +0530")
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Pratik Singhal <ps06756@gmail.com> writes:

> Hello, I am new to freeBSD and trying to contribute to freeBSD.  I have a
> small question.
>
> Whenever I make a small change in the kernel, say apply a patch which only
> affects 1 or 2 files and compile the kernel using the command :-
>
>
> make KERNCONF=config_file buildkernel
>
> It takes a lot of time (around 1 hour) and starts rebuilding the whole
> kernel instead of just building the relevant files.
>
>
> I have checked the freeBSD handbook and checked the targets in Makefile ,
> but none of them provide information about this situation.

Makefile targets specify *what* to build, not *how*.

> How, can I make sure that only the relevant files are built and not the
> whole kernel again and again ?

Try the comments at the top of Makefile.inc1.