On 11/6/2015 9:51 AM, Catalin Marinas wrote:
On Fri, Nov 06, 2015 at 09:39:07AM -0800, Shi, Yang wrote:
On 11/6/2015 9:35 AM, Catalin Marinas wrote:
On Fri, Nov 06, 2015 at 09:23:38AM -0800, Shi, Yang wrote:
On 11/6/2015 8:25 AM, Will Deacon wrote:
However, the patch would allow one to
disable FRAME_POINTERS (not sure it has any effect on the aarch64 gcc
though).
No, it doesn't. Actually, FRAME_POINTER could be disabled regardless of the
patch.
In which case I suggest that we always select it just as a clearer
statement that the feature cannot be disabled (and you never know what
the compiler people decide to do in the future).
Do you mean select FRAME_POINTER in ARCH_WANT_FRAME_POINTERS?
Yes, we could, but this may cause other architectures which select
ARCH_WANT_FRAME_POINTERS to have FRAME_POINTER selected too.
This would have been the ideal option, something like:
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -322,7 +322,7 @@ config ARCH_WANT_FRAME_POINTERS
help
config FRAME_POINTER
- bool "Compile the kernel with frame pointers"
+ bool "Compile the kernel with frame pointers" if
!ARCH_WANT_FRAME_POINTERS
depends on DEBUG_KERNEL && \
(CRIS || M68K || FRV || UML || \
AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || \
But, as you said, we would need to check the other architectures
selecting ARCH_WANT_FRAME_POINTERS.
How about:
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1d1521c..709255a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -319,6 +319,7 @@ config DEBUG_SECTION_MISMATCH
#
config ARCH_WANT_FRAME_POINTERS
bool
+ select FRAME_POINTER if ARM64
help
config FRAME_POINTER
If other architectures want the same behavior, they could easily append
to the is statement. If all arches which selects
ARCH_WANT_FRAME_POINTERS, the if statement could be just removed.
Yang
In the meantime:
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -27,6 +27,7 @@ config ARM64
select CPU_PM if (SUSPEND || CPU_IDLE)
select DCACHE_WORD_ACCESS
select EDAC_SUPPORT
+ select FRAME_POINTER
select GENERIC_ALLOCATOR
select GENERIC_CLOCKEVENTS
select GENERIC_CLOCKEVENTS_BROADCAST
--
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