| Message ID | 1525179614-14571-5-git-send-email-changbin.du@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Good morning. On 05/01/2018 06:00 AM, changbin.du@intel.com wrote: > From: Changbin Du <changbin.du@intel.com> > > > Signed-off-by: Changbin Du <changbin.du@intel.com> > --- > Makefile | 4 ++++ > include/linux/compiler-gcc.h | 2 +- > include/linux/compiler.h | 2 +- > lib/Kconfig.debug | 21 +++++++++++++++++++++ > 4 files changed, 27 insertions(+), 2 deletions(-) > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 90f35ad..2432e77d 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -211,6 +211,27 @@ config NO_AUTO_INLINE > > Use only if you want to debug the kernel. > > +config DEBUG_EXPERIENCE > + bool "Optimize for better debugging experience (-Og)" > + default n > + select NO_AUTO_INLINE > + depends on !CC_OPTIMIZE_FOR_SIZE > + help > + This will apply GCC '-Og' optimization level get supported from which is supported since > + GCC 4.8. This optimization level offers a reasonable level of > + optimization while maintaining fast compilation and a good > + debugging experience. It is similar to '-O1' while perfer keeping while preferring to keep > + debug ability over runtime speed. The overall performance will > + drop a bit. > + > + If enabling this option break your kernel, you should either breaks > + disable this or find a fix (mostly in the arch code). Currently > + this option has only be tested in qemu x86_64 guest. > + > + Use only if you want to debug the kernel, especially if you want > + to have better kernel debugging experience with gdb facilities > + like kgdb and qemu. > + > config ENABLE_WARN_DEPRECATED > bool "Enable __deprecated logic" > default y > thanks,
On Tue, May 01, 2018 at 08:25:27AM -0700, Randy Dunlap wrote: > Good morning. > > On 05/01/2018 06:00 AM, changbin.du@intel.com wrote: > > From: Changbin Du <changbin.du@intel.com> > > > > > > Signed-off-by: Changbin Du <changbin.du@intel.com> > > --- > > Makefile | 4 ++++ > > include/linux/compiler-gcc.h | 2 +- > > include/linux/compiler.h | 2 +- > > lib/Kconfig.debug | 21 +++++++++++++++++++++ > > 4 files changed, 27 insertions(+), 2 deletions(-) > > > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > > index 90f35ad..2432e77d 100644 > > --- a/lib/Kconfig.debug > > +++ b/lib/Kconfig.debug > > @@ -211,6 +211,27 @@ config NO_AUTO_INLINE > > > > Use only if you want to debug the kernel. > > > > +config DEBUG_EXPERIENCE > > + bool "Optimize for better debugging experience (-Og)" > > + default n > > + select NO_AUTO_INLINE > > + depends on !CC_OPTIMIZE_FOR_SIZE > > + help > > + This will apply GCC '-Og' optimization level get supported from > > which is supported since > > > + GCC 4.8. This optimization level offers a reasonable level of > > + optimization while maintaining fast compilation and a good > > + debugging experience. It is similar to '-O1' while perfer keeping > > while preferring to keep > > > + debug ability over runtime speed. The overall performance will > > + drop a bit. > > + > > + If enabling this option break your kernel, you should either > > breaks > > > + disable this or find a fix (mostly in the arch code). Currently > > + this option has only be tested in qemu x86_64 guest. > > + > > + Use only if you want to debug the kernel, especially if you want > > + to have better kernel debugging experience with gdb facilities > > + like kgdb and qemu. > > + > > config ENABLE_WARN_DEPRECATED > > bool "Enable __deprecated logic" > > default y > > > > thanks, > -- > ~Randy Thanks for your correction, I will update.
On Tue, May 1, 2018 at 9:00 AM, <changbin.du@intel.com> wrote: > From: Changbin Du <changbin.du@intel.com> > +config DEBUG_EXPERIENCE > + bool "Optimize for better debugging experience (-Og)" > + default n > + select NO_AUTO_INLINE > + depends on !CC_OPTIMIZE_FOR_SIZE > + help How about having this as another option alongside CC_OPTIMIZE_FOR_SIZE and CC_OPTIMIZE_FOR_PERFORMANCE in the same choice statement? We could also add another option for -Os (for faster compiles) or possibly for -O3 (if anyone cares) in there. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Makefile b/Makefile index eb694f6..6a10469 100644 --- a/Makefile +++ b/Makefile @@ -639,6 +639,9 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation) KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context) +ifdef CONFIG_DEBUG_EXPERIENCE +KBUILD_CFLAGS += $(call cc-option, -Og) +else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += $(call cc-option,-Oz,-Os) KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,) @@ -649,6 +652,7 @@ else KBUILD_CFLAGS += -O2 endif endif +endif KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \ $(call cc-disable-warning,maybe-uninitialized,)) diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index b4bf73f..b8b3832 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -192,7 +192,7 @@ #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) -#ifndef __CHECKER__ +#if !defined(__CHECKER__) && !defined(CONFIG_DEBUG_EXPERIENCE) # define __compiletime_warning(message) __attribute__((warning(message))) # define __compiletime_error(message) __attribute__((error(message))) #endif /* __CHECKER__ */ diff --git a/include/linux/compiler.h b/include/linux/compiler.h index ab4711c..952cc7f 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -301,7 +301,7 @@ unsigned long read_word_at_a_time(const void *addr) * sparse see a constant array size without breaking compiletime_assert on old * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether. */ -# ifndef __CHECKER__ +# if !defined(__CHECKER__) && !defined(CONFIG_DEBUG_EXPERIENCE) # define __compiletime_error_fallback(condition) \ do { ((void)sizeof(char[1 - 2 * condition])); } while (0) # endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 90f35ad..2432e77d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -211,6 +211,27 @@ config NO_AUTO_INLINE Use only if you want to debug the kernel. +config DEBUG_EXPERIENCE + bool "Optimize for better debugging experience (-Og)" + default n + select NO_AUTO_INLINE + depends on !CC_OPTIMIZE_FOR_SIZE + help + This will apply GCC '-Og' optimization level get supported from + GCC 4.8. This optimization level offers a reasonable level of + optimization while maintaining fast compilation and a good + debugging experience. It is similar to '-O1' while perfer keeping + debug ability over runtime speed. The overall performance will + drop a bit. + + If enabling this option break your kernel, you should either + disable this or find a fix (mostly in the arch code). Currently + this option has only be tested in qemu x86_64 guest. + + Use only if you want to debug the kernel, especially if you want + to have better kernel debugging experience with gdb facilities + like kgdb and qemu. + config ENABLE_WARN_DEPRECATED bool "Enable __deprecated logic" default y