From: Sam Ravnborg <sam@ravnborg•org>
To: Anton Vorontsov <avorontsov@ru•mvista.com>
Cc: linux-kernel@vger•kernel.org, linuxppc-dev@ozlabs•org,
Steven Rostedt <srostedt@redhat•com>,
Paul Mackerras <paulus@samba•org>, Ingo Molnar <mingo@elte•hu>
Subject: Re: [PATCH 1/3] powerpc, Makefile: Make it possible to safely select CONFIG_FRAME_POINTER
Date: Sun, 5 Apr 2009 23:07:56 +0200 [thread overview]
Message-ID: <20090405210756.GG24374@uranus.ravnborg.org> (raw)
In-Reply-To: <20090320164429.GA28037@oksana.dev.rtsoft.ru>
On Fri, Mar 20, 2009 at 07:44:29PM +0300, Anton Vorontsov wrote:
> This patch introduces ARCH_HAS_NORMAL_FRAME_POINTERS Kconfig symbol.
> When defined, the top level Makefile won't add -fno-omit-frame-pointer
> cflag (the flag is useless in PowerPC kernels, and also makes gcc
> generate wrong code).
>
> Also move ARCH_WANT_FRAME_POINTERS's help text.
>
> Signed-off-by: Anton Vorontsov <avorontsov@ru•mvista.com>
Hi Anton - sorry for the late feedback.
1) The preferred naming for variables that are supposed to be selcted
are "HAVE_xxxx".
So in this case it would be:
HAVE_NORMAL_FRAME_POINTER
2) I do not really understand the interpretation of normal in this case,
can it be more specific?
Looking at your patch then if specified we use "-fomit-frame-pointer"
in the case where it is set.
So I read it like:
If arch has normal framepointer then we omit them - strange?
3) Indent in top-level MAkefile for new stuff is generally 8 spaces.
Do NOT use tabs as this would confuse make and rener assignmnet non-functional.
4) The individual "HAVE_* members should be sorted alphabetically in the arch
Kconfig file (which they seldomly are :-( )
Sam
> ---
> Makefile | 7 +++++--
> arch/powerpc/Kconfig | 1 +
> lib/Kconfig.debug | 16 ++++++++++------
> 3 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 46c04c5..bf41b05 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -538,9 +538,12 @@ KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
> endif
>
> ifdef CONFIG_FRAME_POINTER
> -KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
> + KBUILD_CFLAGS += -fno-optimize-sibling-calls
> + ifndef ARCH_HAS_NORMAL_FRAME_POINTERS
> + KBUILD_CFLAGS += -fno-omit-frame-pointer
> + endif
> else
> -KBUILD_CFLAGS += -fomit-frame-pointer
> + KBUILD_CFLAGS += -fomit-frame-pointer
> endif
>
> ifdef CONFIG_DEBUG_INFO
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 97f9a64..4587e66 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -113,6 +113,7 @@ config PPC
> select HAVE_FUNCTION_TRACER
> select HAVE_FUNCTION_GRAPH_TRACER
> select ARCH_WANT_OPTIONAL_GPIOLIB
> + select ARCH_HAS_NORMAL_FRAME_POINTERS
> select HAVE_IDE
> select HAVE_IOREMAP_PROT
> select HAVE_EFFICIENT_UNALIGNED_ACCESS
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 4b63b6b..fc8cd1f 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -661,20 +661,24 @@ config DEBUG_NOTIFIERS
> This is a relatively cheap check but if you care about maximum
> performance, say N.
>
> -#
> -# Select this config option from the architecture Kconfig, if it
> -# it is preferred to always offer frame pointers as a config
> -# option on the architecture (regardless of KERNEL_DEBUG):
> -#
> config ARCH_WANT_FRAME_POINTERS
> bool
> help
> + Select this config option from the architecture Kconfig, if it
> + it is preferred to always offer frame pointers as a config
> + option on the architecture (regardless of KERNEL_DEBUG).
> +
> +config ARCH_HAS_NORMAL_FRAME_POINTERS
> + bool
> + help
> + Architectures should select this symbol if their ABI implies
> + having a frame pointer.
>
> config FRAME_POINTER
> bool "Compile the kernel with frame pointers"
> depends on DEBUG_KERNEL && \
> (CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
> - AVR32 || SUPERH || BLACKFIN || MN10300) || \
> + AVR32 || SUPERH || BLACKFIN || MN10300 || PPC) || \
> ARCH_WANT_FRAME_POINTERS
> default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
> help
> --
> 1.5.6.5
>
next prev parent reply other threads:[~2009-04-05 21:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-20 16:44 [PATCH v4 0/3] Tracers vs. CALLER_ADDR on PowerPC Anton Vorontsov
2009-03-20 16:44 ` [PATCH 1/3] powerpc, Makefile: Make it possible to safely select CONFIG_FRAME_POINTER Anton Vorontsov
2009-03-21 3:49 ` Steven Rostedt
2009-03-28 10:48 ` Anton Vorontsov
2009-03-29 22:54 ` Benjamin Herrenschmidt
2009-03-30 4:36 ` Sam Ravnborg
2009-04-05 21:07 ` Sam Ravnborg [this message]
2009-04-13 15:51 ` Steven Rostedt
2009-05-02 0:14 ` Anton Vorontsov
2009-03-20 16:44 ` [PATCH 2/3] powerpc: Remove -fno-omit-frame-pointer workarounds Anton Vorontsov
2009-03-21 3:50 ` Steven Rostedt
2009-03-20 16:44 ` [PATCH 3/3] tracing: Tracers that use CALLER_ADDR macros should select FRAME_POINTER Anton Vorontsov
2009-03-20 16:52 ` [PATCH v4 0/3] Tracers vs. CALLER_ADDR on PowerPC Anton Vorontsov
-- strict thread matches above, loose matches on Subject: below --
2009-05-02 0:13 [PATCH v5 " Anton Vorontsov
2009-05-02 0:14 ` [PATCH 1/3] powerpc, Makefile: Make it possible to safely select CONFIG_FRAME_POINTER Anton Vorontsov
2009-05-02 19:48 ` Segher Boessenkool
2009-05-03 2:04 ` Steven Rostedt
2009-05-05 7:56 ` Segher Boessenkool
2009-05-05 13:33 ` Steven Rostedt
2009-05-05 13:51 ` Segher Boessenkool
2009-05-05 23:11 ` Steven Rostedt
2009-05-18 4:14 ` Benjamin Herrenschmidt
2009-05-18 19:55 ` Segher Boessenkool
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