lkml.org 
[lkml]   [1998]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Shouldn't SMP be an option?
Hi Peter,

> Yes, but I think a lot of things still #include <linux/config.h>,
> which AFAIK is the "old style".

Aha, let me illuminate you (and anyone else on the list that cares). :)

_Everything_ still uses #include <linux/config.h>.

There's a program, scripts/mkdep.c, that takes files and computes
dependencies for them. The classical way to do this is to list all
the #include's.

Werner Almesberger had a bright idea: he changed mkdep.c so that when
a file #include's <linux/config.h>, it *does not* have a dependency on
include/linux/config.h! Instead, it has a lot of little dependencies on
little file. So if foo.c uses CONFIG_FOO_1 and CONFIG_FOO_2, it actually
has a dependency on include/config/foo/1.h and include/config/foo/2.h.

All these files are auto-generated and when you run 'make
config/oldconfig/menuconfig/xconfig', only the configuration options
that change get their little files regenerated.

Try it, take a 2.1.9X kernel, build it, add or subtract a few drivers,
build it again, watch what happens. Check out source/mkdep.c,
Documentation/smart-config.txt, and some of the generated .depend files.

Cheers,

Michael Chastain
<mailto:mec@shout.net>
"love without fear"

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu

\
 
 \ /
  Last update: 2005-03-22 13:42    [W:0.029 / U:0.880 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site