From: Masami Hiramatsu (Google) <[email protected]>
Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
in SH architecture because it does not implement arch_cmpxchg_local().
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
arch/sh/include/asm/cmpxchg.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
index 288f6f38d98f..e920e61fb817 100644
--- a/arch/sh/include/asm/cmpxchg.h
+++ b/arch/sh/include/asm/cmpxchg.h
@@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
(unsigned long)_n_, sizeof(*(ptr))); \
})
+#include <asm-generic/cmpxchg-local.h>
+
#endif /* __ASM_SH_CMPXCHG_H */
On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <[email protected]>
>
> Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> in SH architecture because it does not implement arch_cmpxchg_local().
I do not think this is correct.
The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
disables interrupts), whereas arch/sh can be built SMP. We should probably add
some guards into <asm-generic/cmpxchg-local.h> for that as we have in
<asm-generic/cmpxchg.h>.
I think the right thing to do here is to define arch_cmpxchg_local() in terms
of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add:
#define arch_cmpxchg_local arch_cmpxchg
Mark.
>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> ---
> arch/sh/include/asm/cmpxchg.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> index 288f6f38d98f..e920e61fb817 100644
> --- a/arch/sh/include/asm/cmpxchg.h
> +++ b/arch/sh/include/asm/cmpxchg.h
> @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> (unsigned long)_n_, sizeof(*(ptr))); \
> })
>
> +#include <asm-generic/cmpxchg-local.h>
> +
> #endif /* __ASM_SH_CMPXCHG_H */
>
On Tue, 2023-10-24 at 23:52 +0900, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <[email protected]>
>
> Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> in SH architecture because it does not implement arch_cmpxchg_local().
>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> ---
> arch/sh/include/asm/cmpxchg.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> index 288f6f38d98f..e920e61fb817 100644
> --- a/arch/sh/include/asm/cmpxchg.h
> +++ b/arch/sh/include/asm/cmpxchg.h
> @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> (unsigned long)_n_, sizeof(*(ptr))); \
> })
>
> +#include <asm-generic/cmpxchg-local.h>
> +
> #endif /* __ASM_SH_CMPXCHG_H */
Reviewed-by: John Paul Adrian Glaubitz <[email protected]>
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer
`. `' Physicist
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
On Tue, 24 Oct 2023 16:08:12 +0100
Mark Rutland <[email protected]> wrote:
> On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> > From: Masami Hiramatsu (Google) <[email protected]>
> >
> > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > in SH architecture because it does not implement arch_cmpxchg_local().
>
> I do not think this is correct.
>
> The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
> disables interrupts), whereas arch/sh can be built SMP. We should probably add
> some guards into <asm-generic/cmpxchg-local.h> for that as we have in
> <asm-generic/cmpxchg.h>.
Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
on local CPU?
So I think it doesn't care about the other CPUs (IOW, it should not touched by
other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
defined as raw "cmpxchg" without lock prefix.
#define __cmpxchg_local(ptr, old, new, size) \
__raw_cmpxchg((ptr), (old), (new), (size), "")
Thank you,
>
> I think the right thing to do here is to define arch_cmpxchg_local() in terms
> of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add:
>
> #define arch_cmpxchg_local arch_cmpxchg
>
> Mark.
>
> >
> > Reported-by: kernel test robot <[email protected]>
> > Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> > ---
> > arch/sh/include/asm/cmpxchg.h | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> > index 288f6f38d98f..e920e61fb817 100644
> > --- a/arch/sh/include/asm/cmpxchg.h
> > +++ b/arch/sh/include/asm/cmpxchg.h
> > @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> > (unsigned long)_n_, sizeof(*(ptr))); \
> > })
> >
> > +#include <asm-generic/cmpxchg-local.h>
> > +
> > #endif /* __ASM_SH_CMPXCHG_H */
> >
--
Masami Hiramatsu (Google) <[email protected]>
On 2023/10/25 07:42, Masami Hiramatsu (Google) wrote:
> On Tue, 24 Oct 2023 16:08:12 +0100
> Mark Rutland <[email protected]> wrote:
>
>> On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
>>> From: Masami Hiramatsu (Google) <[email protected]>
>>>
>>> Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
>>> in SH architecture because it does not implement arch_cmpxchg_local().
>>
>> I do not think this is correct.
>>
>> The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
>> disables interrupts), whereas arch/sh can be built SMP. We should probably add
>> some guards into <asm-generic/cmpxchg-local.h> for that as we have in
>> <asm-generic/cmpxchg.h>.
>
> Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
> on local CPU?
asm-generic/cmpxchg.h is only for UP, will throw an error for SMP building:
#ifdef CONFIG_SMP
#error "Cannot use generic cmpxchg on SMP"
#endif
SH arch seems it does have SMP systems. The arch/sh/include/asm/cmpxchg.h has
the following codes:
#if defined(CONFIG_GUSA_RB)
#include <asm/cmpxchg-grb.h>
#elif defined(CONFIG_CPU_SH4A)
#include <asm/cmpxchg-llsc.h>
#elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
#include <asm/cmpxchg-cas.h>
#else
#include <asm/cmpxchg-irq.h>
#endif
> So I think it doesn't care about the other CPUs (IOW, it should not touched by
> other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
> defined as raw "cmpxchg" without lock prefix.
>
> #define __cmpxchg_local(ptr, old, new, size) \
> __raw_cmpxchg((ptr), (old), (new), (size), "")
>
>
> Thank you,
>
>
>>
>> I think the right thing to do here is to define arch_cmpxchg_local() in terms
>> of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add:
>>
>> #define arch_cmpxchg_local arch_cmpxchg
I agree too. Might not be performance optimized but guarantees correctness.
>> Mark.
>>
>>>
>>> Reported-by: kernel test robot <[email protected]>
>>> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
>>> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
>>> ---
>>> arch/sh/include/asm/cmpxchg.h | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
>>> index 288f6f38d98f..e920e61fb817 100644
>>> --- a/arch/sh/include/asm/cmpxchg.h
>>> +++ b/arch/sh/include/asm/cmpxchg.h
>>> @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
>>> (unsigned long)_n_, sizeof(*(ptr))); \
>>> })
>>>
>>> +#include <asm-generic/cmpxchg-local.h>
>>> +
>>> #endif /* __ASM_SH_CMPXCHG_H */
>>>
>
>
On Wed, Oct 25, 2023 at 08:42:55AM +0900, Masami Hiramatsu wrote:
> On Tue, 24 Oct 2023 16:08:12 +0100
> Mark Rutland <[email protected]> wrote:
>
> > On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> > > From: Masami Hiramatsu (Google) <[email protected]>
> > >
> > > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > > in SH architecture because it does not implement arch_cmpxchg_local().
> >
> > I do not think this is correct.
> >
> > The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
> > disables interrupts), whereas arch/sh can be built SMP. We should probably add
> > some guards into <asm-generic/cmpxchg-local.h> for that as we have in
> > <asm-generic/cmpxchg.h>.
>
> Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
> on local CPU?
> So I think it doesn't care about the other CPUs (IOW, it should not touched by
> other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
> defined as raw "cmpxchg" without lock prefix.
>
> #define __cmpxchg_local(ptr, old, new, size) \
> __raw_cmpxchg((ptr), (old), (new), (size), "")
>
Yes, you're right; sorry for the noise.
For your original patch:
Acked-by: Mark Rutland <[email protected]>
Mark.
>
> Thank you,
>
>
> >
> > I think the right thing to do here is to define arch_cmpxchg_local() in terms
> > of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add:
> >
> > #define arch_cmpxchg_local arch_cmpxchg
> >
> > Mark.
> >
> > >
> > > Reported-by: kernel test robot <[email protected]>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > > Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> > > ---
> > > arch/sh/include/asm/cmpxchg.h | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> > > index 288f6f38d98f..e920e61fb817 100644
> > > --- a/arch/sh/include/asm/cmpxchg.h
> > > +++ b/arch/sh/include/asm/cmpxchg.h
> > > @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> > > (unsigned long)_n_, sizeof(*(ptr))); \
> > > })
> > >
> > > +#include <asm-generic/cmpxchg-local.h>
> > > +
> > > #endif /* __ASM_SH_CMPXCHG_H */
> > >
>
>
> --
> Masami Hiramatsu (Google) <[email protected]>
On Wed, 2023-10-25 at 11:30 +0100, Mark Rutland wrote:
> On Wed, Oct 25, 2023 at 08:42:55AM +0900, Masami Hiramatsu wrote:
> > On Tue, 24 Oct 2023 16:08:12 +0100
> > Mark Rutland <[email protected]> wrote:
> >
> > > On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> > > > From: Masami Hiramatsu (Google) <[email protected]>
> > > >
> > > > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > > > in SH architecture because it does not implement arch_cmpxchg_local().
> > >
> > > I do not think this is correct.
> > >
> > > The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
> > > disables interrupts), whereas arch/sh can be built SMP. We should probably add
> > > some guards into <asm-generic/cmpxchg-local.h> for that as we have in
> > > <asm-generic/cmpxchg.h>.
> >
> > Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
> > on local CPU?
> > So I think it doesn't care about the other CPUs (IOW, it should not touched by
> > other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
> > defined as raw "cmpxchg" without lock prefix.
> >
> > #define __cmpxchg_local(ptr, old, new, size) \
> > __raw_cmpxchg((ptr), (old), (new), (size), "")
> >
>
> Yes, you're right; sorry for the noise.
>
> For your original patch:
>
> Acked-by: Mark Rutland <[email protected]>
>
Geert, what's your opinion on this?
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer
`. `' Physicist
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
On 2023/10/25 09:51, wuqiang.matt wrote:
> On 2023/10/25 07:42, Masami Hiramatsu (Google) wrote:
>> On Tue, 24 Oct 2023 16:08:12 +0100
>> Mark Rutland <[email protected]> wrote:
>>
>>> On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
>>>> From: Masami Hiramatsu (Google) <[email protected]>
>>>>
>>>> Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
>>>> in SH architecture because it does not implement arch_cmpxchg_local().
>>>
>>> I do not think this is correct.
>>>
>>> The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
>>> disables interrupts), whereas arch/sh can be built SMP. We should probably add
>>> some guards into <asm-generic/cmpxchg-local.h> for that as we have in
>>> <asm-generic/cmpxchg.h>.
>>
>> Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
>> on local CPU?
>
> asm-generic/cmpxchg.h is only for UP, will throw an error for SMP building:
>
> #ifdef CONFIG_SMP
> #error "Cannot use generic cmpxchg on SMP"
> #endif
Sorry that I just noticed Masami's patch has asm-generic/cmpxchg-local.h
included, not asm-generic/cmpxchg.h. cmpxchg.h does throw an error for SMP
configs, but cmpxchg-local.h doesn't.
> SH arch seems it does have SMP systems. The arch/sh/include/asm/cmpxchg.h has
> the following codes:
>
> #if defined(CONFIG_GUSA_RB)
> #include <asm/cmpxchg-grb.h>
> #elif defined(CONFIG_CPU_SH4A)
> #include <asm/cmpxchg-llsc.h>
> #elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
> #include <asm/cmpxchg-cas.h>
> #else
> #include <asm/cmpxchg-irq.h>
> #endif
>
>> So I think it doesn't care about the other CPUs (IOW, it should not touched by
>> other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
>> defined as raw "cmpxchg" without lock prefix.
>>
>> #define __cmpxchg_local(ptr, old, new, size) \
>> __raw_cmpxchg((ptr), (old), (new), (size), "")
>>
>>
>> Thank you,
>>
>>
>>>
>>> I think the right thing to do here is to define arch_cmpxchg_local() in terms
>>> of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add:
>>>
>>> #define arch_cmpxchg_local arch_cmpxchg
>
> I agree too. Might not be performance optimized but guarantees correctness.
>
>>> Mark.
>>>
>>>>
>>>> Reported-by: kernel test robot <[email protected]>
>>>> Closes:
>>>> https://lore.kernel.org/oe-kbuild-all/[email protected]/
>>>> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
>>>> ---
>>>> arch/sh/include/asm/cmpxchg.h | 2 ++
>>>> 1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
>>>> index 288f6f38d98f..e920e61fb817 100644
>>>> --- a/arch/sh/include/asm/cmpxchg.h
>>>> +++ b/arch/sh/include/asm/cmpxchg.h
>>>> @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void *
>>>> ptr, unsigned long old,
>>>> (unsigned long)_n_, sizeof(*(ptr))); \
>>>> })
>>>> +#include <asm-generic/cmpxchg-local.h>
>>>> +
>>>> #endif /* __ASM_SH_CMPXCHG_H */
>>>>
>>
>>
>
On 2023/10/24 22:52, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <[email protected]>
>
> Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> in SH architecture because it does not implement arch_cmpxchg_local().
>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> ---
> arch/sh/include/asm/cmpxchg.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> index 288f6f38d98f..e920e61fb817 100644
> --- a/arch/sh/include/asm/cmpxchg.h
> +++ b/arch/sh/include/asm/cmpxchg.h
> @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> (unsigned long)_n_, sizeof(*(ptr))); \
> })
>
> +#include <asm-generic/cmpxchg-local.h>
> +
asm-generic/cmpxchg-local.h defines only 2 routines: __generic_cmpxchg_local
and __generic_cmpxchg64_local.
Shall add the definition of arch_cmpxchg_local into
arch/sh/include/asm/cmpxchg.h, or group arch_cmpxchg_local and
arch_cmpxchg64_local into
asm-generic/cmpxchg-local.h ?
> #endif /* __ASM_SH_CMPXCHG_H */
>
Hi Adrian,
On Wed, Oct 25, 2023 at 12:32 PM John Paul Adrian Glaubitz
<[email protected]> wrote:
> On Wed, 2023-10-25 at 11:30 +0100, Mark Rutland wrote:
> > On Wed, Oct 25, 2023 at 08:42:55AM +0900, Masami Hiramatsu wrote:
> > > On Tue, 24 Oct 2023 16:08:12 +0100
> > > Mark Rutland <[email protected]> wrote:
> > > > On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> > > > > From: Masami Hiramatsu (Google) <[email protected]>
> > > > >
> > > > > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > > > > in SH architecture because it does not implement arch_cmpxchg_local().
> > > >
> > > > I do not think this is correct.
> > > >
> > > > The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
> > > > disables interrupts), whereas arch/sh can be built SMP. We should probably add
> > > > some guards into <asm-generic/cmpxchg-local.h> for that as we have in
> > > > <asm-generic/cmpxchg.h>.
> > >
> > > Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
> > > on local CPU?
> > > So I think it doesn't care about the other CPUs (IOW, it should not touched by
> > > other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
> > > defined as raw "cmpxchg" without lock prefix.
> > >
> > > #define __cmpxchg_local(ptr, old, new, size) \
> > > __raw_cmpxchg((ptr), (old), (new), (size), "")
> > >
> >
> > Yes, you're right; sorry for the noise.
> >
> > For your original patch:
> >
> > Acked-by: Mark Rutland <[email protected]>
>
> Geert, what's your opinion on this?
While this looks OK on first sight (ARM includes the same file, even
on SMP), it does not seem to work?
For sh-allnoconfig, as reported by kernel test robot:
$ make ARCH=sh CROSS_COMPILE=sh2-linux- allnoconfig lib/objpool.o
lib/objpool.c: In function 'objpool_try_add_slot':
./include/linux/atomic/atomic-arch-fallback.h:384:27: error: implicit
declaration of function 'arch_cmpxchg_local'; did you mean
'raw_cmpxchg_local'? [-Werror=implicit-function-declaration]
384 | #define raw_cmpxchg_local arch_cmpxchg_local
| ^~~~~~~~~~~~~~~~~~
./include/linux/atomic/atomic-arch-fallback.h:392:16: note: in
expansion of macro 'raw_cmpxchg_local'
392 | ___r = raw_cmpxchg_local((_ptr), ___o, (_new)); \
| ^~~~~~~~~~~~~~~~~
./include/linux/atomic/atomic-instrumented.h:4980:9: note: in
expansion of macro 'raw_try_cmpxchg_local'
4980 | raw_try_cmpxchg_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
| ^~~~~~~~~~~~~~~~~~~~~
lib/objpool.c:169:19: note: in expansion of macro 'try_cmpxchg_local'
169 | } while (!try_cmpxchg_local(&slot->tail, &tail, tail + 1));
| ^~~~~~~~~~~~~~~~~
For an SMP defconfig:
$ make ARCH=sh CROSS_COMPILE=sh4-linux-gnu- sdk7786_defconfig lib/objpool.o
./include/linux/atomic/atomic-arch-fallback.h:384:27: error: implicit
declaration of function ‘arch_cmpxchg_local’; did you mean
‘try_cmpxchg_local’? [-Werror=implicit-function-declaration]
384 | #define raw_cmpxchg_local arch_cmpxchg_local
| ^~~~~~~~~~~~~~~~~~
./include/linux/atomic/atomic-arch-fallback.h:392:16: note: in
expansion of macro ‘raw_cmpxchg_local’
392 | ___r = raw_cmpxchg_local((_ptr), ___o, (_new)); \
| ^~~~~~~~~~~~~~~~~
./include/linux/atomic/atomic-instrumented.h:4980:9: note: in
expansion of macro ‘raw_try_cmpxchg_local’
4980 | raw_try_cmpxchg_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
| ^~~~~~~~~~~~~~~~~~~~~
lib/objpool.c:169:19: note: in expansion of macro ‘try_cmpxchg_local’
169 | } while (!try_cmpxchg_local(&slot->tail, &tail, tail + 1));
| ^~~~~~~~~~~~~~~~~
Hiramatsu-san: do these build for you?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
On Wed, 25 Oct 2023 15:16:16 +0200
Geert Uytterhoeven <[email protected]> wrote:
> Hi Adrian,
>
> On Wed, Oct 25, 2023 at 12:32 PM John Paul Adrian Glaubitz
> <[email protected]> wrote:
> > On Wed, 2023-10-25 at 11:30 +0100, Mark Rutland wrote:
> > > On Wed, Oct 25, 2023 at 08:42:55AM +0900, Masami Hiramatsu wrote:
> > > > On Tue, 24 Oct 2023 16:08:12 +0100
> > > > Mark Rutland <[email protected]> wrote:
> > > > > On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote:
> > > > > > From: Masami Hiramatsu (Google) <[email protected]>
> > > > > >
> > > > > > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > > > > > in SH architecture because it does not implement arch_cmpxchg_local().
> > > > >
> > > > > I do not think this is correct.
> > > > >
> > > > > The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only
> > > > > disables interrupts), whereas arch/sh can be built SMP. We should probably add
> > > > > some guards into <asm-generic/cmpxchg-local.h> for that as we have in
> > > > > <asm-generic/cmpxchg.h>.
> > > >
> > > > Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg
> > > > on local CPU?
> > > > So I think it doesn't care about the other CPUs (IOW, it should not touched by
> > > > other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() is
> > > > defined as raw "cmpxchg" without lock prefix.
> > > >
> > > > #define __cmpxchg_local(ptr, old, new, size) \
> > > > __raw_cmpxchg((ptr), (old), (new), (size), "")
> > > >
> > >
> > > Yes, you're right; sorry for the noise.
> > >
> > > For your original patch:
> > >
> > > Acked-by: Mark Rutland <[email protected]>
> >
> > Geert, what's your opinion on this?
>
> While this looks OK on first sight (ARM includes the same file, even
> on SMP), it does not seem to work?
>
> For sh-allnoconfig, as reported by kernel test robot:
>
> $ make ARCH=sh CROSS_COMPILE=sh2-linux- allnoconfig lib/objpool.o
> lib/objpool.c: In function 'objpool_try_add_slot':
> ./include/linux/atomic/atomic-arch-fallback.h:384:27: error: implicit
> declaration of function 'arch_cmpxchg_local'; did you mean
> 'raw_cmpxchg_local'? [-Werror=implicit-function-declaration]
> 384 | #define raw_cmpxchg_local arch_cmpxchg_local
> | ^~~~~~~~~~~~~~~~~~
> ./include/linux/atomic/atomic-arch-fallback.h:392:16: note: in
> expansion of macro 'raw_cmpxchg_local'
> 392 | ___r = raw_cmpxchg_local((_ptr), ___o, (_new)); \
> | ^~~~~~~~~~~~~~~~~
> ./include/linux/atomic/atomic-instrumented.h:4980:9: note: in
> expansion of macro 'raw_try_cmpxchg_local'
> 4980 | raw_try_cmpxchg_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
> | ^~~~~~~~~~~~~~~~~~~~~
> lib/objpool.c:169:19: note: in expansion of macro 'try_cmpxchg_local'
> 169 | } while (!try_cmpxchg_local(&slot->tail, &tail, tail + 1));
> | ^~~~~~~~~~~~~~~~~
>
> For an SMP defconfig:
>
> $ make ARCH=sh CROSS_COMPILE=sh4-linux-gnu- sdk7786_defconfig lib/objpool.o
>
> ./include/linux/atomic/atomic-arch-fallback.h:384:27: error: implicit
> declaration of function ‘arch_cmpxchg_local’; did you mean
> ‘try_cmpxchg_local’? [-Werror=implicit-function-declaration]
> 384 | #define raw_cmpxchg_local arch_cmpxchg_local
> | ^~~~~~~~~~~~~~~~~~
> ./include/linux/atomic/atomic-arch-fallback.h:392:16: note: in
> expansion of macro ‘raw_cmpxchg_local’
> 392 | ___r = raw_cmpxchg_local((_ptr), ___o, (_new)); \
> | ^~~~~~~~~~~~~~~~~
> ./include/linux/atomic/atomic-instrumented.h:4980:9: note: in
> expansion of macro ‘raw_try_cmpxchg_local’
> 4980 | raw_try_cmpxchg_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
> | ^~~~~~~~~~~~~~~~~~~~~
> lib/objpool.c:169:19: note: in expansion of macro ‘try_cmpxchg_local’
> 169 | } while (!try_cmpxchg_local(&slot->tail, &tail, tail + 1));
> | ^~~~~~~~~~~~~~~~~
>
> Hiramatsu-san: do these build for you?
Thanks for pointing. I thought I just need to include the header file.
That's my fault.
Let me fix that.
Thank you!
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
>
> 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
--
Masami Hiramatsu (Google) <[email protected]>
On Wed, 25 Oct 2023 19:26:37 +0800
"wuqiang.matt" <[email protected]> wrote:
> On 2023/10/24 22:52, Masami Hiramatsu (Google) wrote:
> > From: Masami Hiramatsu (Google) <[email protected]>
> >
> > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation
> > in SH architecture because it does not implement arch_cmpxchg_local().
> >
> > Reported-by: kernel test robot <[email protected]>
> > Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> > ---
> > arch/sh/include/asm/cmpxchg.h | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> > index 288f6f38d98f..e920e61fb817 100644
> > --- a/arch/sh/include/asm/cmpxchg.h
> > +++ b/arch/sh/include/asm/cmpxchg.h
> > @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> > (unsigned long)_n_, sizeof(*(ptr))); \
> > })
> >
> > +#include <asm-generic/cmpxchg-local.h>
> > +
>
> asm-generic/cmpxchg-local.h defines only 2 routines: __generic_cmpxchg_local
> and __generic_cmpxchg64_local.
Thanks Wuqiang, I found how I can fix that from your message.
>
> Shall add the definition of arch_cmpxchg_local into
> arch/sh/include/asm/cmpxchg.h, or group arch_cmpxchg_local and
> arch_cmpxchg64_local into
> asm-generic/cmpxchg-local.h ?
No, maybe it depends on the arch that which __generic function need to use.
Thank you,
>
> > #endif /* __ASM_SH_CMPXCHG_H */
> >
>
--
Masami Hiramatsu (Google) <[email protected]>