Re: [GIT] kbuild core updates for 2.6.39-rc1

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

On Sun, Mar 20, 2011 at 05:53:24PM -0700, Linus Torvalds wrote:
> On Sat, Mar 19, 2011 at 1:58 AM, Michal Marek <mmarek@suse.cz> wrote:
> >
> > * Section mismatch analysis enabled by default
> >  - there are only a few warnings for defconfig builds,
> >    all{yes,mod}config still has a lot of them. Depending on the general
> >    perception of this change, we might disable it later in the rc phase
> >    again.
> 
> No.
> 
> We don't enable stuff like this by default. Not when it actually
> changes some really fundamental compiler flags, and thus the whole "we
> can disable it late in -rc again" is a totally broken option, since if
> we have any compiler issues, we'd want to know it early.
Note that the default y doesn't result from the patch in this pull
request but from 
	1d53661 (blackfin: enable DEBUG_SECTION_MISMATCH)
. I admit I didn't think deeply about it, but keeping it seemed OK for
me.

> And we _know_ we are going to disable it, since it enables the "don't
> inline" flag to gcc for called-once functions. So there's no question
> at all what the default should be in any release kernel.
I wasn't aware of that, Mike so even "default y if BLACKFIN" seems to be
a bad idea.

Michal, do you want just remove the default y and squash it into the
commit?
And something that just occured my now is that the warning about
CONFIG_DEBUG_SECTION_MISMATCH in scripts/mod/modpost.c could get an
update, too.  Something like:

 		warn("modpost: Found %d section mismatch(es).\n"
-		     "To see full details build your kernel with:\n"
-		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
+		     "To see full details enable CONFIG_DEBUG_SECTION_MISMATCH in your .config.\n"
		     sec_mismatch_count);

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |