Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753513AbaGTTXV (ORCPT ); Sun, 20 Jul 2014 15:23:21 -0400 Received: from asavdk4.altibox.net ([109.247.116.15]:43104 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753042AbaGTTXT (ORCPT ); Sun, 20 Jul 2014 15:23:19 -0400 Date: Sun, 20 Jul 2014 21:23:15 +0200 From: Sam Ravnborg To: Andi Kleen Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [PATCH 2/2] Kbuild: Add a option to enable dwarf4 Message-ID: <20140720192315.GA4679@ravnborg.org> References: <1405466172-17055-1-git-send-email-andi@firstfloor.org> <1405466172-17055-2-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1405466172-17055-2-git-send-email-andi@firstfloor.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 16, 2014 at 01:16:12AM +0200, Andi Kleen wrote: > From: Andi Kleen > > I found that a lot of unresolvable variables when using gdb on the kernel > become resolvable when dwarf4 is enabled. So add a Kconfig flag to enable it. > > It definitely increases the debug information size, but on the other > hand this isn't so bad when debug fusion is used. Would it not make sense to try to enable degug info like this: First try -gdwarf-4 If this fails try -gdwarf-3 If this fails try -gdwarf-2 And if this also fails fallback to -g We could then us a Kconfig option to enable the highest debug level - where 4 for now is the highest. On the other hand if most people have revent utils then they all have -gdwarf-4 supported and then it is no big deal. Sam > > Signed-off-by: Andi Kleen > --- > Makefile | 3 +++ > lib/Kconfig.debug | 9 +++++++++ > 2 files changed, 12 insertions(+) > > diff --git a/Makefile b/Makefile > index 953659e..9c4080b 100644 > --- a/Makefile > +++ b/Makefile > @@ -690,6 +690,9 @@ KBUILD_CFLAGS += -g > KBUILD_AFLAGS += -Wa,-gdwarf-2 > endif > endif > +ifdef CONFIG_DEBUG_INFO_DWARF4 > +KBUILD_CFLAGS += -gdwarf-4 > +endif Should we sue $(call cc-option ...) here as not all gcc's supports this today? Sam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/