From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25151 invoked by alias); 27 Jun 2009 20:13:16 -0000 Received: (qmail 25134 invoked by uid 22791); 27 Jun 2009 20:13:15 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from hrndva-omtalb.mail.rr.com (HELO hrndva-omtalb.mail.rr.com) (71.74.56.123) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 27 Jun 2009 20:13:07 +0000 Received: from gandalf ([74.67.89.75]) by hrndva-omta02.mail.rr.com with ESMTP id <20090627201304661.FCDA4042@hrndva-omta02.mail.rr.com>; Sat, 27 Jun 2009 20:13:04 +0000 Date: Sat, 27 Jun 2009 20:13:00 -0000 From: Steven Rostedt To: Masami Hiramatsu cc: Ingo Molnar , Ananth N Mavinakayanahalli , lkml , systemtap , DLE , Jim Keniston , Srikar Dronamraju , Christoph Hellwig , Frederic Weisbecker , "H. Peter Anvin" , Anders Kaseorg , Tim Abbott , sam@ravnborg.org Subject: Re: [RFC][ PATCH -tip v2 3/7] Kbuild: disable gcc crossjumping In-Reply-To: <20090622212313.5384.84166.stgit@localhost.localdomain> Message-ID: References: <20090622212255.5384.53732.stgit@localhost.localdomain> <20090622212313.5384.84166.stgit@localhost.localdomain> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2009-q2/txt/msg01064.txt.bz2 A change like this requires an ACK from Sam Ravnborg. -- Steve On Mon, 22 Jun 2009, Masami Hiramatsu wrote: > Add CONFIG_DISABLE_CROSSJUMP option which disables gcc's cross-function > jumping. This option is required by the kprobes jump optimization. > > Signed-off-by: Masami Hiramatsu > Cc: Ananth N Mavinakayanahalli > Cc: Ingo Molnar > Cc: Jim Keniston > Cc: Srikar Dronamraju > Cc: Christoph Hellwig > Cc: Steven Rostedt > Cc: Frederic Weisbecker > Cc: H. Peter Anvin > Cc: Anders Kaseorg > Cc: Tim Abbott > --- > > Makefile | 4 ++++ > lib/Kconfig.debug | 7 +++++++ > 2 files changed, 11 insertions(+), 0 deletions(-) > > diff --git a/Makefile b/Makefile > index 2903e13..f73b139 100644 > --- a/Makefile > +++ b/Makefile > @@ -524,6 +524,10 @@ else > KBUILD_CFLAGS += -O2 > endif > > +ifdef CONFIG_DISABLE_CROSSJUMP > +KBUILD_CFLAGS += -fno-crossjumping > +endif > + > include $(srctree)/arch/$(SRCARCH)/Makefile > > ifneq ($(CONFIG_FRAME_WARN),0) > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 8da7467..f88e6b8 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -673,6 +673,13 @@ config FRAME_POINTER > larger and slower, but it gives very useful debugging information > in case of kernel bugs. (precise oopses/stacktraces/warnings) > > +config DISABLE_CROSSJUMP > + bool "Disable cross-function jump optimization" > + help > + This build option disables cross-function jump optimization > + (crossjumping) of gcc. Disabling crossjumping might increase > + kernel binary size a little. > + > config BOOT_PRINTK_DELAY > bool "Delay each boot printk message by N milliseconds" > depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY > > > -- > Masami Hiramatsu > > Software Engineer > Hitachi Computer Products (America), Inc. > Software Solutions Division > > e-mail: mhiramat@redhat.com >