Messages in this thread |  | | | Date | Mon, 13 Aug 2012 15:39:54 -0700 | | From | Randy Dunlap <> | | Subject | Re: [PATCH 1/1] boot: Put initcall_debug into its own Kconfig option DEBUG_INITCALL |
| |
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 > <konrad.wilk@oracle.com <mailto:konrad.wilk@oracle.com>> 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 <blquythai@gmail.com > <mailto:blquythai@gmail.com>> > > Reviewed-by: Josh Triplett <josh@joshtriplett.org > <mailto:josh@joshtriplett.org>> > > --- > > 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 > > --
|  |