Hi Yamada-san,
On Fri, Aug 30, 2019 at 5:44 AM Masahiro Yamada
[off-list ref] wrote:
Commit 9012d011660e ("compiler: allow all arches to enable
CONFIG_OPTIMIZE_INLINING") allowed all architectures to enable
this option. A couple of build errors were reported by randconfig,
but all of them have been ironed out.
Towards the goal of removing CONFIG_OPTIMIZE_INLINING entirely
(and it will simplify the 'inline' macro in compiler_types.h),
this commit changes it to always-on option. Going forward, the
compiler will always be allowed to not inline functions marked
'inline'.
This is not a problem for x86 since it has been long used by
arch/x86/configs/{x86_64,i386}_defconfig.
I am keeping the config option just in case any problem crops up for
other architectures.
The code clean-up will be done after confirming this is solid.
Signed-off-by: Masahiro Yamada <redacted>
This breaks compiling drivers/video/fbdev/c2p*, as the functions in
drivers/video/fbdev/c2p_core.h are no longer inlined, leading to calls
to the non-existent function c2p_unsupported(), as reported by KISSKB:
On Thu, Sep 26, 2019 at 5:02 AM [off-list ref] wrote:
FAILED linux-next/m68k-defconfig/m68k Thu Sep 26, 12:58
http://kisskb.ellerman.id.au/kisskb/buildresult/13973194/
Commit: Add linux-next specific files for 20190925
d47175169c28eedd2cc2ab8c01f38764cb0269cc
Compiler: m68k-linux-gcc (GCC) 4.6.3 / GNU ld (GNU Binutils) 2.22
Possible errors
---------------
c2p_planar.c:(.text+0xd6): undefined reference to `c2p_unsupported'
c2p_planar.c:(.text+0x1dc): undefined reference to `c2p_unsupported'
c2p_iplan2.c:(.text+0xc4): undefined reference to `c2p_unsupported'
c2p_iplan2.c:(.text+0x150): undefined reference to `c2p_unsupported'
make[1]: *** [Makefile:1074: vmlinux] Error 1
make: *** [Makefile:179: sub-make] Error 2
I managed to reproduce this with gcc version 8.3.0 (Ubuntu
8.3.0-6ubuntu1~18.04.1) , and bisected the failure to commit
025f072e5823947c ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly") .
Marking the functions __always_inline instead of inline fixes that.
Shall I send a patch to do that?
Thanks!
quoted hunk ↗ jump to hunk
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -327,7 +327,7 @@ config HEADERS_CHECK
relevant for userspace, say 'Y'.
config OPTIMIZE_INLINING
- bool "Allow compiler to uninline functions marked 'inline'"
+ def_bool y
help
This option determines if the kernel forces gcc to inline the functions
developers have marked 'inline'. Doing so takes away freedom from gcc to@@ -338,8 +338,6 @@ config OPTIMIZE_INLINING
decision will become the default in the future. Until then this option
is there to test gcc for this.
- If unsure, say N.
-
config DEBUG_SECTION_MISMATCH
bool "Enable full Section mismatch analysis"
help
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds