Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754169Ab2HMWhP (ORCPT ); Mon, 13 Aug 2012 18:37:15 -0400 Received: from oproxy11-pub.bluehost.com ([173.254.64.10]:45559 "HELO oproxy11-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754059Ab2HMWhN (ORCPT ); Mon, 13 Aug 2012 18:37:13 -0400 Message-ID: <5029823A.9020207@xenotime.net> Date: Mon, 13 Aug 2012 15:39:54 -0700 From: Randy Dunlap Organization: YPO4 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Thai Bui CC: Konrad Rzeszutek Wilk , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] boot: Put initcall_debug into its own Kconfig option DEBUG_INITCALL References: <1344891431-30869-1-git-send-email-blquythai@gmail.com> <20120813212151.GA15429@phenom.dumpdata.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Identified-User: {1807:box742.bluehost.com:xenotime:xenotime.net} {sentby:smtp auth 64.134.136.30 authed with rdunlap@xenotime.net} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4536 Lines: 120 On 08/13/2012 03:08 PM, Thai Bui wrote: > Hi all, > > I am as part of a capstone group at Portland State University is working > to tinify the kernel as small as possible. The ultimate goal is to make > the kernel small enough to use on micro-controller (or under < 200k). > This patch is one of them, it saves 176 bytes on a minimal configuration > of the kernel (the bzImage file was reduced from 363264 bytes to 363264 > bytes applying this patch). > > Aside from the purpose of reducing the size of the kernel. We are also > trying to clean up the kernel by making Kconfig options to compile out > the stuffs that aren't used often. IMO the kernel already has too many kconfig options. Also, personally I would not merge a patch that saves so little memory, especially on what I consider a very useful option. > On Mon, Aug 13, 2012 at 5:21 PM, Konrad Rzeszutek Wilk > > wrote: > > On Mon, Aug 13, 2012 at 01:57:11PM -0700, Thai Bui wrote: > > Putting DEBUG_INITCALL config option to compile out the > command-line option > > "initcall_debug". > > Can you explain the benfits of this please? > > > > Signed-off-by: Thai Bui > > > Reviewed-by: Josh Triplett > > > --- > > Documentation/kernel-parameters.txt | 3 ++- > > include/linux/init.h | 4 ++++ > > init/main.c | 2 ++ > > lib/Kconfig.debug | 9 +++++++++ > > 4 files changed, 17 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/kernel-parameters.txt > b/Documentation/kernel-parameters.txt > > index d99fd9c..3dbaf15 100644 > > --- a/Documentation/kernel-parameters.txt > > +++ b/Documentation/kernel-parameters.txt > > @@ -1026,7 +1026,8 @@ bytes respectively. Such letter suffixes > can also be entirely omitted. > > > > initcall_debug [KNL] Trace initcalls as they are executed. > Useful > > for working out where the kernel is dying > during > > - startup. > > + startup. DEBUG_INITCALL needs to be enabled > in order > > + for this option to work. > > > > initrd= [BOOT] Specify the location of the initial > ramdisk > > > > diff --git a/include/linux/init.h b/include/linux/init.h > > index 6b95109..d2f31f1 100644 > > --- a/include/linux/init.h > > +++ b/include/linux/init.h > > @@ -157,7 +157,11 @@ void prepare_namespace(void); > > > > extern void (*late_time_init)(void); > > > > +#ifdef CONFIG_DEBUG_INITCALL > > extern bool initcall_debug; > > +#else > > +static const bool initcall_debug = false; > > +#endif /* CONFIG_DEBUG_INITCALL */ > > > > #endif > > > > diff --git a/init/main.c b/init/main.c > > index ff49a6d..65837f7 100644 > > --- a/init/main.c > > +++ b/init/main.c > > @@ -648,8 +648,10 @@ static void __init do_ctors(void) > > #endif > > } > > > > +#ifdef CONFIG_DEBUG_INITCALL > > bool initcall_debug; > > core_param(initcall_debug, initcall_debug, bool, 0644); > > +#endif /* CONFIG_DEBUG_INITCALL */ > > > > static char msgbuf[64]; > > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > > index 8745ac7..424ac93 100644 > > --- a/lib/Kconfig.debug > > +++ b/lib/Kconfig.debug > > @@ -769,6 +769,15 @@ config DEBUG_WRITECOUNT > > > > If unsure, say N. > > > > +config DEBUG_INITCALL > > + bool "Debug initcalls as they are executed" > > + depends on DEBUG_KERNEL > > + help > > + Enable this for tracing initcalls during startup. Useful > for working > > + out where the kernel is dying during startup. > > + > > + If unsure, say N > > + > > config DEBUG_MEMORY_INIT > > bool "Debug memory initialisation" if EXPERT > > default !EXPERT > > -- -- 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/