Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Christophe, On Tue, Mar 26, 2019 at 3:03 PM Christophe Leroy wrote: > > Hi Masahiro, > > Le 25/03/2019 à 07:44, Masahiro Yamada a écrit : > > Hi Christophe, > > > > > > On Sat, Mar 23, 2019 at 5:27 PM LEROY Christophe > > wrote: > >> > >> Arnd Bergmann a écrit : > >> > >>> On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote: > > I've added your patch to my randconfig test setup and will let you > know if I see anything noticeable. I'm currently testing clang-arm32, > clang-arm64 and gcc-x86. > >>> > >>> This is the only additional bug that has come up so far: > >>> > >>> `.exit.text' referenced in section `.alt.smp.init' of > >>> drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section > >>> `exit.text' of drivers/char/ipmi/ipmi_msghandler.o > >> > >> Wouldn't it be useful to activate -Winline gcc warning to ease finding > >> out problematic usage of inline keyword ? > > > > > > Yes, it is useful to find out > > which function is causing the error. > > Thanks for the tip. > > > > I did a mass build on kisskb. Almost ok, see results at > http://kisskb.ellerman.id.au/kisskb/head/203d912edf8dde291977c71aa64024065e197f79/ > > ps3_defconfig with GCC 5 fails > (http://kisskb.ellerman.id.au/kisskb/buildresult/13742711/) with: > > arch/powerpc/mm/tlb-radix.c:148:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > arch/powerpc/mm/tlb-radix.c:148:2: error: impossible constraint in 'asm' > arch/powerpc/mm/tlb-radix.c:118:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > > ps3_defconfig with GCC 4.6 fails > (http://kisskb.ellerman.id.au/kisskb/buildresult/13742591/) with: > > arch/powerpc/mm/tlb-radix.c:148:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > arch/powerpc/mm/tlb-radix.c:118:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't > match constraints [-Werror] > > randconfig with GCC 4.6 fails > (http://kisskb.ellerman.id.au/kisskb/buildresult/13742698/) with: > > arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm' Thanks. I fixed these ppc errors, and separate out arch-fixes. Now, the latest version is v3. -- Best Regards Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
* Masahiro Yamada wrote:
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
>
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
>
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
>
> I tested this patch on my arm/arm64 boards.
>
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
>
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
>
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
>
> This also slightly improves the "Kernel hacking" Kconfig menu.
> Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
> mentioned this config option would be a good fit in the "compiler option"
> menu. I did so.
No objections against moving it from x86 code to generic code.
Thanks,
Ingo
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Masahiro, Le 25/03/2019 à 07:44, Masahiro Yamada a écrit : Hi Christophe, On Sat, Mar 23, 2019 at 5:27 PM LEROY Christophe wrote: Arnd Bergmann a écrit : On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote: I've added your patch to my randconfig test setup and will let you know if I see anything noticeable. I'm currently testing clang-arm32, clang-arm64 and gcc-x86. This is the only additional bug that has come up so far: `.exit.text' referenced in section `.alt.smp.init' of drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section `exit.text' of drivers/char/ipmi/ipmi_msghandler.o Wouldn't it be useful to activate -Winline gcc warning to ease finding out problematic usage of inline keyword ? Yes, it is useful to find out which function is causing the error. Thanks for the tip. I did a mass build on kisskb. Almost ok, see results at http://kisskb.ellerman.id.au/kisskb/head/203d912edf8dde291977c71aa64024065e197f79/ ps3_defconfig with GCC 5 fails (http://kisskb.ellerman.id.au/kisskb/buildresult/13742711/) with: arch/powerpc/mm/tlb-radix.c:148:2: error: asm operand 3 probably doesn't match constraints [-Werror] arch/powerpc/mm/tlb-radix.c:148:2: error: impossible constraint in 'asm' arch/powerpc/mm/tlb-radix.c:118:2: error: asm operand 3 probably doesn't match constraints [-Werror] arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't match constraints [-Werror] ps3_defconfig with GCC 4.6 fails (http://kisskb.ellerman.id.au/kisskb/buildresult/13742591/) with: arch/powerpc/mm/tlb-radix.c:148:2: error: asm operand 3 probably doesn't match constraints [-Werror] arch/powerpc/mm/tlb-radix.c:118:2: error: asm operand 3 probably doesn't match constraints [-Werror] arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't match constraints [-Werror] randconfig with GCC 4.6 fails (http://kisskb.ellerman.id.au/kisskb/buildresult/13742698/) with: arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm' Christophe
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Mon, Mar 25, 2019 at 8:55 AM Masahiro Yamada wrote: > > On Mon, Mar 25, 2019 at 4:33 PM Arnd Bergmann wrote: > > > > On Mon, Mar 25, 2019 at 7:11 AM Masahiro Yamada > > wrote: > > > I do not know why to reproduce it, > > > but is "__init __noreturn" more sensible than > > > "__always_inline" here? > > > > It's in a header file, so it has to be 'inline'. We could make it > > static inline __init __noreturn, > > Yes, I like 'static inline __init __noreturn' > > > but I don't see an advantage over > > __always_inline there. > > __always_inline takes away the compiler's freedom. > > I'd like to leave it up to the compiler where possible. Ok, fair enough. Arnd
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 2:34 PM Arnd Bergmann wrote: > > On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote: > > > > I've added your patch to my randconfig test setup and will let you > > know if I see anything noticeable. I'm currently testing clang-arm32, > > clang-arm64 and gcc-x86. > > This is the only additional bug that has come up so far: > > `.exit.text' referenced in section `.alt.smp.init' of > drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section > `exit.text' of drivers/char/ipmi/ipmi_msghandler.o FWIW, the message up there does not match the patch anyway, that was an unrelated bug. Arnd
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Mon, Mar 25, 2019 at 4:33 PM Arnd Bergmann wrote:
>
> On Mon, Mar 25, 2019 at 7:11 AM Masahiro Yamada
> wrote:
> > On Wed, Mar 20, 2019 at 10:34 PM Arnd Bergmann wrote:
> > >
> > > On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
> > > >
> > > > I've added your patch to my randconfig test setup and will let you
> > > > know if I see anything noticeable. I'm currently testing clang-arm32,
> > > > clang-arm64 and gcc-x86.
> > >
> > > This is the only additional bug that has come up so far:
> > >
> > > `.exit.text' referenced in section `.alt.smp.init' of
> > > drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
> > > `exit.text' of drivers/char/ipmi/ipmi_msghandler.o
> > >
> > > diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
> > > index 201100226301..84b12e33104d 100644
> > > --- a/arch/arm/kernel/atags.h
> > > +++ b/arch/arm/kernel/atags.h
> > > @@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
> > > const struct machine_desc *setup_machine_tags(phys_addr_t
> > > __atags_pointer,
> > > unsigned int machine_nr);
> > > #else
> > > -static inline const struct machine_desc *
> > > +static __always_inline const struct machine_desc *
> > > setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
> > > {
> > > early_print("no ATAGS support: can't continue\n");
> > >
> >
> >
> > I do not know why to reproduce it,
> > but is "__init __noreturn" more sensible than
> > "__always_inline" here?
>
> It's in a header file, so it has to be 'inline'. We could make it
> static inline __init __noreturn,
Yes, I like 'static inline __init __noreturn'
> but I don't see an advantage over
> __always_inline there.
__always_inline takes away the compiler's freedom.
I'd like to leave it up to the compiler where possible.
The inlining decision may change
depending on -O2, -Os, -Og(which was rejected)
or whatever optimization strategy.
>
> Arnd
>
> __
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
--
Best Regards
Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Mon, Mar 25, 2019 at 7:11 AM Masahiro Yamada
wrote:
> On Wed, Mar 20, 2019 at 10:34 PM Arnd Bergmann wrote:
> >
> > On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
> > >
> > > I've added your patch to my randconfig test setup and will let you
> > > know if I see anything noticeable. I'm currently testing clang-arm32,
> > > clang-arm64 and gcc-x86.
> >
> > This is the only additional bug that has come up so far:
> >
> > `.exit.text' referenced in section `.alt.smp.init' of
> > drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
> > `exit.text' of drivers/char/ipmi/ipmi_msghandler.o
> >
> > diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
> > index 201100226301..84b12e33104d 100644
> > --- a/arch/arm/kernel/atags.h
> > +++ b/arch/arm/kernel/atags.h
> > @@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
> > const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
> > unsigned int machine_nr);
> > #else
> > -static inline const struct machine_desc *
> > +static __always_inline const struct machine_desc *
> > setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
> > {
> > early_print("no ATAGS support: can't continue\n");
> >
>
>
> I do not know why to reproduce it,
> but is "__init __noreturn" more sensible than
> "__always_inline" here?
It's in a header file, so it has to be 'inline'. We could make it
static inline __init __noreturn, but I don't see an advantage over
__always_inline there.
Arnd
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Christophe, On Sat, Mar 23, 2019 at 5:27 PM LEROY Christophe wrote: > > Arnd Bergmann a écrit : > > > On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote: > >> > >> I've added your patch to my randconfig test setup and will let you > >> know if I see anything noticeable. I'm currently testing clang-arm32, > >> clang-arm64 and gcc-x86. > > > > This is the only additional bug that has come up so far: > > > > `.exit.text' referenced in section `.alt.smp.init' of > > drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section > > `exit.text' of drivers/char/ipmi/ipmi_msghandler.o > > Wouldn't it be useful to activate -Winline gcc warning to ease finding > out problematic usage of inline keyword ? Yes, it is useful to find out which function is causing the error. Thanks for the tip. -- Best Regards Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Heiko,
On Thu, Mar 21, 2019 at 5:02 PM Heiko Carstens
wrote:
>
> On Wed, Mar 20, 2019 at 03:20:27PM +0900, Masahiro Yamada wrote:
> > Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> > CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
> >
> > The idea is obviously arch-agnostic although we need some code fixups.
> > This commit moves the config entry from arch/x86/Kconfig.debug to
> > lib/Kconfig.debug so that all architectures (except MIPS for now) can
> > benefit from it.
> >
> > At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> > for MIPS was complex to me.
> >
> > I tested this patch on my arm/arm64 boards.
> >
> > This can make a huge difference in kernel image size especially when
> > CONFIG_OPTIMIZE_FOR_SIZE is enabled.
> >
> > For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
> >
> > dec file
> > 18983424 arch/arm64/boot/Image.before
> > 18321920 arch/arm64/boot/Image.after
>
> Well, this will change, since now people (have to) start adding
> __always_inline annotations on all architectures, most likely until
> all have about the same amount of annotations like x86. This will
> reduce the benefit.
If people start to replace inline with __always_inline here and there,
yes, the difference will be reduced.
Perhaps, we might end up with fixing dozens of places or so,
but I guess we would still get benefit.
> Not sure if it's really a win that we get the inline vs
> __always_inline discussion now on all architectures.
This feature is not x86-specific.
I prefer "do it for all arches or don't do it at all"
instead of the half-baked state.
If we force inlining for the 'inline' marker
there is no point of having __always_inline.
--
Best Regards
Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Mon, Mar 25, 2019 at 3:10 PM Masahiro Yamada
wrote:
>
> Hi Arnd,
>
>
>
>
> On Wed, Mar 20, 2019 at 10:34 PM Arnd Bergmann wrote:
> >
> > On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
> > >
> > > I've added your patch to my randconfig test setup and will let you
> > > know if I see anything noticeable. I'm currently testing clang-arm32,
> > > clang-arm64 and gcc-x86.
> >
> > This is the only additional bug that has come up so far:
> >
> > `.exit.text' referenced in section `.alt.smp.init' of
> > drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
> > `exit.text' of drivers/char/ipmi/ipmi_msghandler.o
> >
> > diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
> > index 201100226301..84b12e33104d 100644
> > --- a/arch/arm/kernel/atags.h
> > +++ b/arch/arm/kernel/atags.h
> > @@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
> > const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
> > unsigned int machine_nr);
> > #else
> > -static inline const struct machine_desc *
> > +static __always_inline const struct machine_desc *
> > setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
> > {
> > early_print("no ATAGS support: can't continue\n");
> >
>
>
> I do not know why to reproduce it,
"how to"
> but is "__init __noreturn" more sensible than
> "__always_inline" here?
>
>
> --
> Best Regards
> Masahiro Yamada
--
Best Regards
Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Arnd,
On Wed, Mar 20, 2019 at 10:34 PM Arnd Bergmann wrote:
>
> On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
> >
> > I've added your patch to my randconfig test setup and will let you
> > know if I see anything noticeable. I'm currently testing clang-arm32,
> > clang-arm64 and gcc-x86.
>
> This is the only additional bug that has come up so far:
>
> `.exit.text' referenced in section `.alt.smp.init' of
> drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
> `exit.text' of drivers/char/ipmi/ipmi_msghandler.o
>
> diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
> index 201100226301..84b12e33104d 100644
> --- a/arch/arm/kernel/atags.h
> +++ b/arch/arm/kernel/atags.h
> @@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
> const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
> unsigned int machine_nr);
> #else
> -static inline const struct machine_desc *
> +static __always_inline const struct machine_desc *
> setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
> {
> early_print("no ATAGS support: can't continue\n");
>
I do not know why to reproduce it,
but is "__init __noreturn" more sensible than
"__always_inline" here?
--
Best Regards
Masahiro Yamada
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Arnd,
On Wed, Mar 20, 2019 at 10:05 PM Arnd Bergmann wrote:
>
> On Wed, Mar 20, 2019 at 11:19 AM Masahiro Yamada
> wrote:
> > On Wed, Mar 20, 2019 at 6:39 PM Arnd Bergmann wrote:
> > >
> > > On Wed, Mar 20, 2019 at 7:41 AM Masahiro Yamada
> > > wrote:
> > >
> > > > It is unclear to me how to fix it.
> > > > That's why I ended up with "depends on !MIPS".
> > > >
> > > >
> > > > MODPOST vmlinux.o
> > > > arch/mips/mm/sc-mips.o: In function `mips_sc_prefetch_enable.part.2':
> > > > sc-mips.c:(.text+0x98): undefined reference to `mips_gcr_base'
> > > > sc-mips.c:(.text+0x9c): undefined reference to `mips_gcr_base'
> > > > sc-mips.c:(.text+0xbc): undefined reference to `mips_gcr_base'
> > > > sc-mips.c:(.text+0xc8): undefined reference to `mips_gcr_base'
> > > > sc-mips.c:(.text+0xdc): undefined reference to `mips_gcr_base'
> > > > arch/mips/mm/sc-mips.o:sc-mips.c:(.text.unlikely+0x44): more undefined
> > > > references to `mips_gcr_base'
> > > >
> > > >
> > > > Perhaps, MIPS folks may know how to fix it.
> > >
> > > I would guess like this:
> > >
> > > diff --git a/arch/mips/include/asm/mips-cm.h
> > > b/arch/mips/include/asm/mips-cm.h
> > > index 8bc5df49b0e1..a27483fedb7d 100644
> > > --- a/arch/mips/include/asm/mips-cm.h
> > > +++ b/arch/mips/include/asm/mips-cm.h
> > > @@ -79,7 +79,7 @@ static inline int mips_cm_probe(void)
> > > *
> > > * Returns true if a CM is present in the system, else false.
> > > */
> > > -static inline bool mips_cm_present(void)
> > > +static __always_inline bool mips_cm_present(void)
> > > {
> > > #ifdef CONFIG_MIPS_CM
> > > return mips_gcr_base != NULL;
> > > @@ -93,7 +93,7 @@ static inline bool mips_cm_present(void)
> > > *
> > > * Returns true if the system implements an L2-only sync region, else
> > > false.
> > > */
> > > -static inline bool mips_cm_has_l2sync(void)
> > > +static __always_inline bool mips_cm_has_l2sync(void)
> > > {
> > > #ifdef CONFIG_MIPS_CM
> > > return mips_cm_l2sync_base != NULL;
> > >
> >
> >
> > Thanks, I applied the above, but I still see
> > undefined reference to `mips_gcr_base'
> >
> >
> > I attached .config to produce this error.
> >
> > I use prebuilt mips-linux-gcc from
> > https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/
>
> I got to this patch experimentally, it fixes the problem for me:
>
> diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
> index 394673991bab..d70d02da038b 100644
> --- a/arch/mips/mm/sc-mips.c
> +++ b/arch/mips/mm/sc-mips.c
> @@ -181,7 +181,7 @@ static int __init mips_sc_probe_cm3(void)
> return 0;
> }
>
> -static inline int __init mips_sc_probe(void)
> +static __always_inline int __init mips_sc_probe(void)
> {
> struct cpuinfo_mips *c = _cpu_data;
> unsigned int config1, config2;
> diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
> index 830c93a010c3..186c28463bf3 100644
> --- a/arch/mips/include/asm/bitops.h
> +++ b/arch/mips/include/asm/bitops.h
> @@ -548,7 +548,7 @@ static inline unsigned long __fls(unsigned long word)
> * Returns 0..SZLONG-1
> * Undefined if no bit exists, so code should check against 0 first.
> */
> -static inline unsigned long __ffs(unsigned long word)
> +static __always_inline unsigned long __ffs(unsigned long word)
> {
> return __fls(word & -word);
> }
>
>
> It does look like a gcc bug though, as at least some of the references
> are from a function that got split out from an inlined function but that
> has no remaining call sites.
>
>Arnd
I applied it, but
"undefined reference to `mips_gcr_base'" still remains.
Then, I got a solution. This is it:
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index 830c93a..6a26ead 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -482,7 +482,7 @@ static inline void __clear_bit_unlock(unsigned
long nr, volatile unsigned long *
* Return the bit position (0..63) of the most significant 1 bit in a word
* Returns -1 if no 1 bit exists
*/
-static inline unsigned long __fls(unsigned long word)
+static __always_inline unsigned long __fls(unsigned long word)
{
int num;
LEROY Christophe provided me a tip
to find out the cause of the error.
-Winline pin-points which function
was not inlined despite of its inline marker.
$ make -j8 ARCH=mips CROSS_COMPILE=mips-linux- KCFLAGS=-Winline
arch/mips/mm/sc-mips.o
CC scripts/mod/devicetable-offsets.s
CC scripts/mod/empty.o
MKELF scripts/mod/elfconfig.h
HOSTCC scripts/mod/modpost.o
HOSTCC scripts/mod/sumversion.o
HOSTCC scripts/mod/file2alias.o
HOSTLD scripts/mod/modpost
CC kernel/bounds.s
CALLscripts/atomic/check-atomics.sh
CC arch/mips/kernel/asm-offsets.s
CALLscripts/checksyscalls.sh
:1478:2: warning: #warning syscall pidfd_send_signal not
implemented [-Wcpp]
:1481:2: warning: #warning syscall io_uring_setup not implemented
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Masahiro Yamada a écrit :
Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
The idea is obviously arch-agnostic although we need some code fixups.
This commit moves the config entry from arch/x86/Kconfig.debug to
lib/Kconfig.debug so that all architectures (except MIPS for now) can
benefit from it.
At this moment, I added "depends on !MIPS" because fixing 0day bot reports
for MIPS was complex to me.
I tested this patch on my arm/arm64 boards.
This can make a huge difference in kernel image size especially when
CONFIG_OPTIMIZE_FOR_SIZE is enabled.
For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
dec file
18983424 arch/arm64/boot/Image.before
18321920 arch/arm64/boot/Image.after
This also slightly improves the "Kernel hacking" Kconfig menu.
Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
mentioned this config option would be a good fit in the "compiler option"
menu. I did so.
I fixed up some files to avoid build warnings/errors.
[1] arch/arm64/include/asm/cpufeature.h
In file included from ././include/linux/compiler_types.h:68,
from :
./arch/arm64/include/asm/jump_label.h: In function 'cpus_have_const_cap':
./include/linux/compiler-gcc.h:120:38: warning: asm operand 0
probably doesn't match constraints
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
^~~
./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of
macro 'asm_volatile_goto'
asm_volatile_goto(
^
./include/linux/compiler-gcc.h:120:38: error: impossible constraint in 'asm'
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
^~~
./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of
macro 'asm_volatile_goto'
asm_volatile_goto(
^
[2] arch/mips/kernel/cpu-bugs64.c
arch/mips/kernel/cpu-bugs64.c: In function 'mult_sh_align_mod.constprop':
arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably
doesn't match constraints [-Werror]
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably
doesn't match constraints [-Werror]
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
asm volatile(
^~~
[3] arch/powerpc/mm/tlb-radix.c
arch/powerpc/mm/tlb-radix.c: In function '__radix__flush_tlb_range_psize':
arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably
doesn't match constraints [-Werror]
asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
^~~
arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm'
CC arch/powerpc/perf/hv-gpci.o
[4] arch/s390/include/asm/cpacf.h
In file included from arch/s390/crypto/des_s390.c:19:
./arch/s390/include/asm/cpacf.h: In function 'cpacf_query':
./arch/s390/include/asm/cpacf.h:170:2: warning: asm operand 3
probably doesn't match constraints
asm volatile(
^~~
./arch/s390/include/asm/cpacf.h:170:2: error: impossible constraint in 'asm'
[5] arch/powerpc/kernel/prom_init.c
WARNING: vmlinux.o(.text.unlikely+0x20): Section mismatch in
reference from the function .prom_getprop() to the function
.init.text:.call_prom()
The function .prom_getprop() references
the function __init .call_prom().
This is often because .prom_getprop lacks a __init
annotation or the annotation of .call_prom is wrong.
WARNING: vmlinux.o(.text.unlikely+0x3c): Section mismatch in
reference from the function .prom_getproplen() to the function
.init.text:.call_prom()
The function .prom_getproplen() references
the function __init .call_prom().
This is often because .prom_getproplen lacks a __init
annotation or the annotation of .call_prom is wrong.
[6] drivers/mtd/nand/raw/vf610_nfc.c
drivers/mtd/nand/raw/vf610_nfc.c: In function ‘vf610_nfc_cmd’:
drivers/mtd/nand/raw/vf610_nfc.c:455:3: warning: ‘offset’ may be
used uninitialized in this function [-Wmaybe-uninitialized]
vf610_nfc_rd_from_sram(instr->ctx.data.buf.in + offset,
^~~
nfc->regs + NFC_MAIN_AREA(0) + offset,
~~
trfr_sz, !nfc->data_access);
~~~
[7] arch/arm/kernel/smp.c
arch/arm/kernel/smp.c: In function ‘raise_nmi’:
arch/arm/kernel/smp.c:522:2: warning: array subscript is above array
bounds [-Warray-bounds]
trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
^
The fixup is not included in this. The patch is available in ML:
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-February/409393.html
Signed-off-by: Masahiro Yamada
---
arch/arm64/include/asm/cpufeature.h | 4 ++--
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Arnd Bergmann a écrit :
On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
I've added your patch to my randconfig test setup and will let you
know if I see anything noticeable. I'm currently testing clang-arm32,
clang-arm64 and gcc-x86.
This is the only additional bug that has come up so far:
`.exit.text' referenced in section `.alt.smp.init' of
drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
`exit.text' of drivers/char/ipmi/ipmi_msghandler.o
Wouldn't it be useful to activate -Winline gcc warning to ease finding
out problematic usage of inline keyword ?
Christophe
diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
index 201100226301..84b12e33104d 100644
--- a/arch/arm/kernel/atags.h
+++ b/arch/arm/kernel/atags.h
@@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
unsigned int machine_nr);
#else
-static inline const struct machine_desc *
+static __always_inline const struct machine_desc *
setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
{
early_print("no ATAGS support: can't continue\n");
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 03:20:27PM +0900, Masahiro Yamada wrote:
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
>
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
>
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
>
> I tested this patch on my arm/arm64 boards.
>
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
>
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
>
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
Well, this will change, since now people (have to) start adding
__always_inline annotations on all architectures, most likely until
all have about the same amount of annotations like x86. This will
reduce the benefit.
Not sure if it's really a win that we get the inline vs
__always_inline discussion now on all architectures.
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 10:41 AM Arnd Bergmann wrote:
>
> I've added your patch to my randconfig test setup and will let you
> know if I see anything noticeable. I'm currently testing clang-arm32,
> clang-arm64 and gcc-x86.
This is the only additional bug that has come up so far:
`.exit.text' referenced in section `.alt.smp.init' of
drivers/char/ipmi/ipmi_msghandler.o: defined in discarded section
`exit.text' of drivers/char/ipmi/ipmi_msghandler.o
diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
index 201100226301..84b12e33104d 100644
--- a/arch/arm/kernel/atags.h
+++ b/arch/arm/kernel/atags.h
@@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tags);
const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
unsigned int machine_nr);
#else
-static inline const struct machine_desc *
+static __always_inline const struct machine_desc *
setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
{
early_print("no ATAGS support: can't continue\n");
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 11:19 AM Masahiro Yamada
wrote:
> On Wed, Mar 20, 2019 at 6:39 PM Arnd Bergmann wrote:
> >
> > On Wed, Mar 20, 2019 at 7:41 AM Masahiro Yamada
> > wrote:
> >
> > > It is unclear to me how to fix it.
> > > That's why I ended up with "depends on !MIPS".
> > >
> > >
> > > MODPOST vmlinux.o
> > > arch/mips/mm/sc-mips.o: In function `mips_sc_prefetch_enable.part.2':
> > > sc-mips.c:(.text+0x98): undefined reference to `mips_gcr_base'
> > > sc-mips.c:(.text+0x9c): undefined reference to `mips_gcr_base'
> > > sc-mips.c:(.text+0xbc): undefined reference to `mips_gcr_base'
> > > sc-mips.c:(.text+0xc8): undefined reference to `mips_gcr_base'
> > > sc-mips.c:(.text+0xdc): undefined reference to `mips_gcr_base'
> > > arch/mips/mm/sc-mips.o:sc-mips.c:(.text.unlikely+0x44): more undefined
> > > references to `mips_gcr_base'
> > >
> > >
> > > Perhaps, MIPS folks may know how to fix it.
> >
> > I would guess like this:
> >
> > diff --git a/arch/mips/include/asm/mips-cm.h
> > b/arch/mips/include/asm/mips-cm.h
> > index 8bc5df49b0e1..a27483fedb7d 100644
> > --- a/arch/mips/include/asm/mips-cm.h
> > +++ b/arch/mips/include/asm/mips-cm.h
> > @@ -79,7 +79,7 @@ static inline int mips_cm_probe(void)
> > *
> > * Returns true if a CM is present in the system, else false.
> > */
> > -static inline bool mips_cm_present(void)
> > +static __always_inline bool mips_cm_present(void)
> > {
> > #ifdef CONFIG_MIPS_CM
> > return mips_gcr_base != NULL;
> > @@ -93,7 +93,7 @@ static inline bool mips_cm_present(void)
> > *
> > * Returns true if the system implements an L2-only sync region, else
> > false.
> > */
> > -static inline bool mips_cm_has_l2sync(void)
> > +static __always_inline bool mips_cm_has_l2sync(void)
> > {
> > #ifdef CONFIG_MIPS_CM
> > return mips_cm_l2sync_base != NULL;
> >
>
>
> Thanks, I applied the above, but I still see
> undefined reference to `mips_gcr_base'
>
>
> I attached .config to produce this error.
>
> I use prebuilt mips-linux-gcc from
> https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/
I got to this patch experimentally, it fixes the problem for me:
diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
index 394673991bab..d70d02da038b 100644
--- a/arch/mips/mm/sc-mips.c
+++ b/arch/mips/mm/sc-mips.c
@@ -181,7 +181,7 @@ static int __init mips_sc_probe_cm3(void)
return 0;
}
-static inline int __init mips_sc_probe(void)
+static __always_inline int __init mips_sc_probe(void)
{
struct cpuinfo_mips *c = _cpu_data;
unsigned int config1, config2;
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index 830c93a010c3..186c28463bf3 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -548,7 +548,7 @@ static inline unsigned long __fls(unsigned long word)
* Returns 0..SZLONG-1
* Undefined if no bit exists, so code should check against 0 first.
*/
-static inline unsigned long __ffs(unsigned long word)
+static __always_inline unsigned long __ffs(unsigned long word)
{
return __fls(word & -word);
}
It does look like a gcc bug though, as at least some of the references
are from a function that got split out from an inlined function but that
has no remaining call sites.
Arnd
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Hi Arnd,
On Wed, Mar 20, 2019 at 6:39 PM Arnd Bergmann wrote:
>
> On Wed, Mar 20, 2019 at 7:41 AM Masahiro Yamada
> wrote:
>
> > It is unclear to me how to fix it.
> > That's why I ended up with "depends on !MIPS".
> >
> >
> > MODPOST vmlinux.o
> > arch/mips/mm/sc-mips.o: In function `mips_sc_prefetch_enable.part.2':
> > sc-mips.c:(.text+0x98): undefined reference to `mips_gcr_base'
> > sc-mips.c:(.text+0x9c): undefined reference to `mips_gcr_base'
> > sc-mips.c:(.text+0xbc): undefined reference to `mips_gcr_base'
> > sc-mips.c:(.text+0xc8): undefined reference to `mips_gcr_base'
> > sc-mips.c:(.text+0xdc): undefined reference to `mips_gcr_base'
> > arch/mips/mm/sc-mips.o:sc-mips.c:(.text.unlikely+0x44): more undefined
> > references to `mips_gcr_base'
> >
> >
> > Perhaps, MIPS folks may know how to fix it.
>
> I would guess like this:
>
> diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
> index 8bc5df49b0e1..a27483fedb7d 100644
> --- a/arch/mips/include/asm/mips-cm.h
> +++ b/arch/mips/include/asm/mips-cm.h
> @@ -79,7 +79,7 @@ static inline int mips_cm_probe(void)
> *
> * Returns true if a CM is present in the system, else false.
> */
> -static inline bool mips_cm_present(void)
> +static __always_inline bool mips_cm_present(void)
> {
> #ifdef CONFIG_MIPS_CM
> return mips_gcr_base != NULL;
> @@ -93,7 +93,7 @@ static inline bool mips_cm_present(void)
> *
> * Returns true if the system implements an L2-only sync region, else false.
> */
> -static inline bool mips_cm_has_l2sync(void)
> +static __always_inline bool mips_cm_has_l2sync(void)
> {
> #ifdef CONFIG_MIPS_CM
> return mips_cm_l2sync_base != NULL;
>
Thanks, I applied the above, but I still see
undefined reference to `mips_gcr_base'
I attached .config to produce this error.
I use prebuilt mips-linux-gcc from
https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/
--
Best Regards
Masahiro Yamada
config.gz
Description: application/gzip
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 7:21 AM Masahiro Yamada
wrote:
>
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
>
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
>
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
>
> I tested this patch on my arm/arm64 boards.
>
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
>
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
>
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
>
> This also slightly improves the "Kernel hacking" Kconfig menu.
> Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
> mentioned this config option would be a good fit in the "compiler option"
> menu. I did so.
I think this is a good idea in general, but it is likely to cause a lot of
new warnings. Especially the -Wmaybe-uninitialized warnings get
new false positives every time we get substantially different inlining
decisions.
I've added your patch to my randconfig test setup and will let you
know if I see anything noticeable. I'm currently testing clang-arm32,
clang-arm64 and gcc-x86.
Arnd
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 7:41 AM Masahiro Yamada
wrote:
> It is unclear to me how to fix it.
> That's why I ended up with "depends on !MIPS".
>
>
> MODPOST vmlinux.o
> arch/mips/mm/sc-mips.o: In function `mips_sc_prefetch_enable.part.2':
> sc-mips.c:(.text+0x98): undefined reference to `mips_gcr_base'
> sc-mips.c:(.text+0x9c): undefined reference to `mips_gcr_base'
> sc-mips.c:(.text+0xbc): undefined reference to `mips_gcr_base'
> sc-mips.c:(.text+0xc8): undefined reference to `mips_gcr_base'
> sc-mips.c:(.text+0xdc): undefined reference to `mips_gcr_base'
> arch/mips/mm/sc-mips.o:sc-mips.c:(.text.unlikely+0x44): more undefined
> references to `mips_gcr_base'
>
>
> Perhaps, MIPS folks may know how to fix it.
I would guess like this:
diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 8bc5df49b0e1..a27483fedb7d 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -79,7 +79,7 @@ static inline int mips_cm_probe(void)
*
* Returns true if a CM is present in the system, else false.
*/
-static inline bool mips_cm_present(void)
+static __always_inline bool mips_cm_present(void)
{
#ifdef CONFIG_MIPS_CM
return mips_gcr_base != NULL;
@@ -93,7 +93,7 @@ static inline bool mips_cm_present(void)
*
* Returns true if the system implements an L2-only sync region, else false.
*/
-static inline bool mips_cm_has_l2sync(void)
+static __always_inline bool mips_cm_has_l2sync(void)
{
#ifdef CONFIG_MIPS_CM
return mips_cm_l2sync_base != NULL;
Re: [PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
On Wed, Mar 20, 2019 at 3:21 PM Masahiro Yamada
wrote:
>
> Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
> CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
>
> The idea is obviously arch-agnostic although we need some code fixups.
> This commit moves the config entry from arch/x86/Kconfig.debug to
> lib/Kconfig.debug so that all architectures (except MIPS for now) can
> benefit from it.
>
> At this moment, I added "depends on !MIPS" because fixing 0day bot reports
> for MIPS was complex to me.
BTW, I got the following error if I enabled CONFIG_OPTIMIZE_INLINING for MIPS.
It is unclear to me how to fix it.
That's why I ended up with "depends on !MIPS".
MODPOST vmlinux.o
arch/mips/mm/sc-mips.o: In function `mips_sc_prefetch_enable.part.2':
sc-mips.c:(.text+0x98): undefined reference to `mips_gcr_base'
sc-mips.c:(.text+0x9c): undefined reference to `mips_gcr_base'
sc-mips.c:(.text+0xbc): undefined reference to `mips_gcr_base'
sc-mips.c:(.text+0xc8): undefined reference to `mips_gcr_base'
sc-mips.c:(.text+0xdc): undefined reference to `mips_gcr_base'
arch/mips/mm/sc-mips.o:sc-mips.c:(.text.unlikely+0x44): more undefined
references to `mips_gcr_base'
Perhaps, MIPS folks may know how to fix it.
> I tested this patch on my arm/arm64 boards.
>
> This can make a huge difference in kernel image size especially when
> CONFIG_OPTIMIZE_FOR_SIZE is enabled.
>
> For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
>
> dec file
> 18983424 arch/arm64/boot/Image.before
> 18321920 arch/arm64/boot/Image.after
>
> This also slightly improves the "Kernel hacking" Kconfig menu.
> Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
> mentioned this config option would be a good fit in the "compiler option"
> menu. I did so.
>
> I fixed up some files to avoid build warnings/errors.
>
> [1] arch/arm64/include/asm/cpufeature.h
>
> In file included from ././include/linux/compiler_types.h:68,
> from :
> ./arch/arm64/include/asm/jump_label.h: In function 'cpus_have_const_cap':
> ./include/linux/compiler-gcc.h:120:38: warning: asm operand 0 probably
> doesn't match constraints
> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
> ^~~
> ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro
> 'asm_volatile_goto'
> asm_volatile_goto(
> ^
> ./include/linux/compiler-gcc.h:120:38: error: impossible constraint in 'asm'
> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
> ^~~
> ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro
> 'asm_volatile_goto'
> asm_volatile_goto(
> ^
>
> [2] arch/mips/kernel/cpu-bugs64.c
>
> arch/mips/kernel/cpu-bugs64.c: In function 'mult_sh_align_mod.constprop':
> arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't
> match constraints [-Werror]
> asm volatile(
> ^~~
> arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't
> match constraints [-Werror]
> asm volatile(
> ^~~
> arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
> asm volatile(
> ^~~
> arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
> asm volatile(
> ^~~
>
> [3] arch/powerpc/mm/tlb-radix.c
>
> arch/powerpc/mm/tlb-radix.c: In function '__radix__flush_tlb_range_psize':
> arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't
> match constraints [-Werror]
> asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
> ^~~
> arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm'
> CC arch/powerpc/perf/hv-gpci.o
>
> [4] arch/s390/include/asm/cpacf.h
>
> In file included from arch/s390/crypto/des_s390.c:19:
> ./arch/s390/include/asm/cpacf.h: In function 'cpacf_query':
> ./arch/s390/include/asm/cpacf.h:170:2: warning: asm operand 3 probably
> doesn't match constraints
> asm volatile(
> ^~~
> ./arch/s390/include/asm/cpacf.h:170:2: error: impossible constraint in 'asm'
>
> [5] arch/powerpc/kernel/prom_init.c
>
> WARNING: vmlinux.o(.text.unlikely+0x20): Section mismatch in reference from
> the function .prom_getprop() to the function .init.text:.call_prom()
> The function .prom_getprop() references
> the function __init .call_prom().
> This is often because .prom_getprop lacks a __init
> annotation or the annotation of .call_prom is wrong.
>
> WARNING: vmlinux.o(.text.unlikely+0x3c): Section mismatch in reference from
> the function .prom_getproplen() to the function .init.text:.call_prom()
> The function .prom_getproplen() references
> the function __init .call_prom().
> This is often because .prom_getproplen lacks a __init
> annotation or the annotation of .call_prom is wrong.
>
> [6] drivers/mtd/nand/raw/vf610_nfc.c
>
> drivers/mtd/nand/raw/vf610_nfc.c: In function ‘vf610_nfc_cmd’:
>
[PATCH] compiler: allow all arches to enable CONFIG_OPTIMIZE_INLINING
Commit 60a3cdd06394 ("x86: add optimized inlining") introduced
CONFIG_OPTIMIZE_INLINING, but it has been available only for x86.
The idea is obviously arch-agnostic although we need some code fixups.
This commit moves the config entry from arch/x86/Kconfig.debug to
lib/Kconfig.debug so that all architectures (except MIPS for now) can
benefit from it.
At this moment, I added "depends on !MIPS" because fixing 0day bot reports
for MIPS was complex to me.
I tested this patch on my arm/arm64 boards.
This can make a huge difference in kernel image size especially when
CONFIG_OPTIMIZE_FOR_SIZE is enabled.
For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1.
dec file
18983424 arch/arm64/boot/Image.before
18321920 arch/arm64/boot/Image.after
This also slightly improves the "Kernel hacking" Kconfig menu.
Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen')
mentioned this config option would be a good fit in the "compiler option"
menu. I did so.
I fixed up some files to avoid build warnings/errors.
[1] arch/arm64/include/asm/cpufeature.h
In file included from ././include/linux/compiler_types.h:68,
from :
./arch/arm64/include/asm/jump_label.h: In function 'cpus_have_const_cap':
./include/linux/compiler-gcc.h:120:38: warning: asm operand 0 probably doesn't
match constraints
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
^~~
./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro
'asm_volatile_goto'
asm_volatile_goto(
^
./include/linux/compiler-gcc.h:120:38: error: impossible constraint in 'asm'
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
^~~
./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro
'asm_volatile_goto'
asm_volatile_goto(
^
[2] arch/mips/kernel/cpu-bugs64.c
arch/mips/kernel/cpu-bugs64.c: In function 'mult_sh_align_mod.constprop':
arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't match
constraints [-Werror]
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't match
constraints [-Werror]
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
asm volatile(
^~~
arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm'
asm volatile(
^~~
[3] arch/powerpc/mm/tlb-radix.c
arch/powerpc/mm/tlb-radix.c: In function '__radix__flush_tlb_range_psize':
arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't match
constraints [-Werror]
asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
^~~
arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm'
CC arch/powerpc/perf/hv-gpci.o
[4] arch/s390/include/asm/cpacf.h
In file included from arch/s390/crypto/des_s390.c:19:
./arch/s390/include/asm/cpacf.h: In function 'cpacf_query':
./arch/s390/include/asm/cpacf.h:170:2: warning: asm operand 3 probably doesn't
match constraints
asm volatile(
^~~
./arch/s390/include/asm/cpacf.h:170:2: error: impossible constraint in 'asm'
[5] arch/powerpc/kernel/prom_init.c
WARNING: vmlinux.o(.text.unlikely+0x20): Section mismatch in reference from the
function .prom_getprop() to the function .init.text:.call_prom()
The function .prom_getprop() references
the function __init .call_prom().
This is often because .prom_getprop lacks a __init
annotation or the annotation of .call_prom is wrong.
WARNING: vmlinux.o(.text.unlikely+0x3c): Section mismatch in reference from the
function .prom_getproplen() to the function .init.text:.call_prom()
The function .prom_getproplen() references
the function __init .call_prom().
This is often because .prom_getproplen lacks a __init
annotation or the annotation of .call_prom is wrong.
[6] drivers/mtd/nand/raw/vf610_nfc.c
drivers/mtd/nand/raw/vf610_nfc.c: In function ‘vf610_nfc_cmd’:
drivers/mtd/nand/raw/vf610_nfc.c:455:3: warning: ‘offset’ may be used
uninitialized in this function [-Wmaybe-uninitialized]
vf610_nfc_rd_from_sram(instr->ctx.data.buf.in + offset,
^~~
nfc->regs + NFC_MAIN_AREA(0) + offset,
~~
trfr_sz, !nfc->data_access);
~~~
[7] arch/arm/kernel/smp.c
arch/arm/kernel/smp.c: In function ‘raise_nmi’:
arch/arm/kernel/smp.c:522:2: warning: array subscript is above array bounds
[-Warray-bounds]
trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
^
The fixup is not included in this. The patch is available in ML:
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-February/409393.html
Signed-off-by: Masahiro Yamada
---
arch/arm64/include/asm/cpufeature.h | 4 ++--
arch/mips/kernel/cpu-bugs64.c | 4 ++--
