diff mbox series

[03/34] powerpc: Use CONFIG_PREEMPTION

Message ID 20191015191821.11479-4-bigeasy@linutronix.de (mailing list archive)
State Not Applicable
Headers show
Series None | expand

Commit Message

Sebastian Andrzej Siewior Oct. 15, 2019, 7:17 p.m. UTC 
From: Thomas Gleixner <tglx@linutronix.de>

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT
output in __die().

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: +traps.c, Kconfig]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/powerpc/Kconfig           | 2 +-
 arch/powerpc/kernel/entry_32.S | 4 ++--
 arch/powerpc/kernel/entry_64.S | 4 ++--
 arch/powerpc/kernel/traps.c    | 7 ++++++-
 4 files changed, 11 insertions(+), 6 deletions(-)

Comments

Christophe Leroy Oct. 16, 2019, 4:57 a.m. UTC | #1 
Le 15/10/2019 à 21:17, Sebastian Andrzej Siewior a écrit :
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
> Both PREEMPT and PREEMPT_RT require the same functionality which today
> depends on CONFIG_PREEMPT.
> 
> Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT
> output in __die().

powerpc doesn't select ARCH_SUPPORTS_RT, so this change is useless as 
CONFIG_PREEMPT_RT cannot be selected.

> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> [bigeasy: +traps.c, Kconfig]
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>   arch/powerpc/Kconfig           | 2 +-
>   arch/powerpc/kernel/entry_32.S | 4 ++--
>   arch/powerpc/kernel/entry_64.S | 4 ++--
>   arch/powerpc/kernel/traps.c    | 7 ++++++-
>   4 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 3e56c9c2f16ee..8ead8d6e1cbc8 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -106,7 +106,7 @@ config LOCKDEP_SUPPORT
>   config GENERIC_LOCKBREAK
>   	bool
>   	default y
> -	depends on SMP && PREEMPT
> +	depends on SMP && PREEMPTION
>   
>   config GENERIC_HWEIGHT
>   	bool
> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
> index d60908ea37fb9..e1a4c39b83b86 100644
> --- a/arch/powerpc/kernel/entry_32.S
> +++ b/arch/powerpc/kernel/entry_32.S
> @@ -897,7 +897,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
>   	bne-	0b
>   1:
>   
> -#ifdef CONFIG_PREEMPT
> +#ifdef CONFIG_PREEMPTION
>   	/* check current_thread_info->preempt_count */
>   	lwz	r0,TI_PREEMPT(r2)
>   	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
> @@ -921,7 +921,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
>   	 */
>   	bl	trace_hardirqs_on
>   #endif
> -#endif /* CONFIG_PREEMPT */
> +#endif /* CONFIG_PREEMPTION */
>   restore_kuap:
>   	kuap_restore r1, r2, r9, r10, r0
>   
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 6467bdab8d405..83733376533e8 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -840,7 +840,7 @@ _GLOBAL(ret_from_except_lite)
>   	bne-	0b
>   1:
>   
> -#ifdef CONFIG_PREEMPT
> +#ifdef CONFIG_PREEMPTION
>   	/* Check if we need to preempt */
>   	andi.	r0,r4,_TIF_NEED_RESCHED
>   	beq+	restore
> @@ -871,7 +871,7 @@ _GLOBAL(ret_from_except_lite)
>   	li	r10,MSR_RI
>   	mtmsrd	r10,1		  /* Update machine state */
>   #endif /* CONFIG_PPC_BOOK3E */
> -#endif /* CONFIG_PREEMPT */
> +#endif /* CONFIG_PREEMPTION */
>   
>   	.globl	fast_exc_return_irq
>   fast_exc_return_irq:
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 82f43535e6867..23d2f20be4f2e 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -252,14 +252,19 @@ NOKPROBE_SYMBOL(oops_end);
>   
>   static int __die(const char *str, struct pt_regs *regs, long err)
>   {
> +	const char *pr = "";
> +

Please follow the same approach as already existing. Don't add a local 
var for that.

>   	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
>   
> +	if (IS_ENABLED(CONFIG_PREEMPTION))
> +		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
> +

drop

>   	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n",

Add one %s

>   	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
>   	       PAGE_SIZE / 1024,
>   	       early_radix_enabled() ? " MMU=Radix" : "",
>   	       early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ? " MMU=Hash" : "",
> -	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",

Replace by: 	IS_ENABLED(CONFIG_PREEMPTION) ? " PREEMPT" : ""

> +	       pr,

add something like: IS_ENABLED(CONFIG_PREEMPT_RT) ? "_RT" : ""

>   	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
>   	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
>   	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
> 

Christophe
Sebastian Andrzej Siewior Oct. 16, 2019, 7:48 a.m. UTC | #2 
On 2019-10-16 06:57:48 [+0200], Christophe Leroy wrote:
> 
> 
> Le 15/10/2019 à 21:17, Sebastian Andrzej Siewior a écrit :
> > From: Thomas Gleixner <tglx@linutronix.de>
> > 
> > CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
> > Both PREEMPT and PREEMPT_RT require the same functionality which today
> > depends on CONFIG_PREEMPT.
> > 
> > Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT
> > output in __die().
> 
> powerpc doesn't select ARCH_SUPPORTS_RT, so this change is useless as
> CONFIG_PREEMPT_RT cannot be selected.

No it is not. It makes it possible for PowerPC to select it one day and
I have patches for it today. Also, if other ARCH copies code from
PowerPC it will copy the correct thing (as in distinguish between the
flavour PREEMPT and the functionality PREEMPTION).

> > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> > index 82f43535e6867..23d2f20be4f2e 100644
> > --- a/arch/powerpc/kernel/traps.c
> > +++ b/arch/powerpc/kernel/traps.c
> > @@ -252,14 +252,19 @@ NOKPROBE_SYMBOL(oops_end);
> >   static int __die(const char *str, struct pt_regs *regs, long err)
> >   {
> > +	const char *pr = "";
> > +
> 
> Please follow the same approach as already existing. Don't add a local var
> for that.

I would leave it to the maintainer to comment on that and decide which
one they want. My eyes find it more readable and the compiles does not
create more code.

> >   	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
> > +	if (IS_ENABLED(CONFIG_PREEMPTION))
> > +		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
> > +
> 
> drop
> 
> >   	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n",
> 
> Add one %s
> 
> >   	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
> >   	       PAGE_SIZE / 1024,
> >   	       early_radix_enabled() ? " MMU=Radix" : "",
> >   	       early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ? " MMU=Hash" : "",
> > -	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
> 
> Replace by: 	IS_ENABLED(CONFIG_PREEMPTION) ? " PREEMPT" : ""
> 
> > +	       pr,
> 
> add something like: IS_ENABLED(CONFIG_PREEMPT_RT) ? "_RT" : ""

this on the other hand will create more code which is not strictly
required.

> >   	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
> >   	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
> >   	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
> > 
> 
> Christophe

Sebastian
Michael Ellerman Oct. 16, 2019, 9:33 a.m. UTC | #3 
Christophe Leroy <christophe.leroy@c-s.fr> writes:
> Le 15/10/2019 à 21:17, Sebastian Andrzej Siewior a écrit :
>> From: Thomas Gleixner <tglx@linutronix.de>
>> 
>> CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
>> Both PREEMPT and PREEMPT_RT require the same functionality which today
>> depends on CONFIG_PREEMPT.
>> 
>> Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT
>> output in __die().
>
> powerpc doesn't select ARCH_SUPPORTS_RT, so this change is useless as 
> CONFIG_PREEMPT_RT cannot be selected.

Yeah I don't think there's any point adding the "_RT" to the __die()
output until/if we ever start supporting PREEMPT_RT.

cheers


>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 3e56c9c2f16ee..8ead8d6e1cbc8 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -106,7 +106,7 @@ config LOCKDEP_SUPPORT
>>   config GENERIC_LOCKBREAK
>>   	bool
>>   	default y
>> -	depends on SMP && PREEMPT
>> +	depends on SMP && PREEMPTION
>>   
>>   config GENERIC_HWEIGHT
>>   	bool
>> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
>> index d60908ea37fb9..e1a4c39b83b86 100644
>> --- a/arch/powerpc/kernel/entry_32.S
>> +++ b/arch/powerpc/kernel/entry_32.S
>> @@ -897,7 +897,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
>>   	bne-	0b
>>   1:
>>   
>> -#ifdef CONFIG_PREEMPT
>> +#ifdef CONFIG_PREEMPTION
>>   	/* check current_thread_info->preempt_count */
>>   	lwz	r0,TI_PREEMPT(r2)
>>   	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
>> @@ -921,7 +921,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
>>   	 */
>>   	bl	trace_hardirqs_on
>>   #endif
>> -#endif /* CONFIG_PREEMPT */
>> +#endif /* CONFIG_PREEMPTION */
>>   restore_kuap:
>>   	kuap_restore r1, r2, r9, r10, r0
>>   
>> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
>> index 6467bdab8d405..83733376533e8 100644
>> --- a/arch/powerpc/kernel/entry_64.S
>> +++ b/arch/powerpc/kernel/entry_64.S
>> @@ -840,7 +840,7 @@ _GLOBAL(ret_from_except_lite)
>>   	bne-	0b
>>   1:
>>   
>> -#ifdef CONFIG_PREEMPT
>> +#ifdef CONFIG_PREEMPTION
>>   	/* Check if we need to preempt */
>>   	andi.	r0,r4,_TIF_NEED_RESCHED
>>   	beq+	restore
>> @@ -871,7 +871,7 @@ _GLOBAL(ret_from_except_lite)
>>   	li	r10,MSR_RI
>>   	mtmsrd	r10,1		  /* Update machine state */
>>   #endif /* CONFIG_PPC_BOOK3E */
>> -#endif /* CONFIG_PREEMPT */
>> +#endif /* CONFIG_PREEMPTION */
>>   
>>   	.globl	fast_exc_return_irq
>>   fast_exc_return_irq:
>> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
>> index 82f43535e6867..23d2f20be4f2e 100644
>> --- a/arch/powerpc/kernel/traps.c
>> +++ b/arch/powerpc/kernel/traps.c
>> @@ -252,14 +252,19 @@ NOKPROBE_SYMBOL(oops_end);
>>   
>>   static int __die(const char *str, struct pt_regs *regs, long err)
>>   {
>> +	const char *pr = "";
>> +
>
> Please follow the same approach as already existing. Don't add a local 
> var for that.
>
>>   	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
>>   
>> +	if (IS_ENABLED(CONFIG_PREEMPTION))
>> +		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
>> +
>
> drop
>
>>   	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n",
>
> Add one %s
>
>>   	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
>>   	       PAGE_SIZE / 1024,
>>   	       early_radix_enabled() ? " MMU=Radix" : "",
>>   	       early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ? " MMU=Hash" : "",
>> -	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
>
> Replace by: 	IS_ENABLED(CONFIG_PREEMPTION) ? " PREEMPT" : ""
>
>> +	       pr,
>
> add something like: IS_ENABLED(CONFIG_PREEMPT_RT) ? "_RT" : ""
>
>>   	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
>>   	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
>>   	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
>> 
>
> Christophe
Sebastian Andrzej Siewior Oct. 16, 2019, 9:35 a.m. UTC | #4 
On 2019-10-16 20:33:08 [+1100], Michael Ellerman wrote:
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
> > Le 15/10/2019 à 21:17, Sebastian Andrzej Siewior a écrit :
> >> From: Thomas Gleixner <tglx@linutronix.de>
> >> 
> >> CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
> >> Both PREEMPT and PREEMPT_RT require the same functionality which today
> >> depends on CONFIG_PREEMPT.
> >> 
> >> Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT
> >> output in __die().
> >
> > powerpc doesn't select ARCH_SUPPORTS_RT, so this change is useless as 
> > CONFIG_PREEMPT_RT cannot be selected.
> 
> Yeah I don't think there's any point adding the "_RT" to the __die()
> output until/if we ever start supporting PREEMPT_RT.

so jut the PREEMPT -> PREEMPTION  bits then?

> cheers

Sebastian
diff mbox series

Patch

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3e56c9c2f16ee..8ead8d6e1cbc8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -106,7 +106,7 @@  config LOCKDEP_SUPPORT
 config GENERIC_LOCKBREAK
 	bool
 	default y
-	depends on SMP && PREEMPT
+	depends on SMP && PREEMPTION
 
 config GENERIC_HWEIGHT
 	bool
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index d60908ea37fb9..e1a4c39b83b86 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -897,7 +897,7 @@  user_exc_return:		/* r10 contains MSR_KERNEL here */
 	bne-	0b
 1:
 
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	/* check current_thread_info->preempt_count */
 	lwz	r0,TI_PREEMPT(r2)
 	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
@@ -921,7 +921,7 @@  user_exc_return:		/* r10 contains MSR_KERNEL here */
 	 */
 	bl	trace_hardirqs_on
 #endif
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
 restore_kuap:
 	kuap_restore r1, r2, r9, r10, r0
 
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6467bdab8d405..83733376533e8 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -840,7 +840,7 @@  _GLOBAL(ret_from_except_lite)
 	bne-	0b
 1:
 
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	/* Check if we need to preempt */
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	beq+	restore
@@ -871,7 +871,7 @@  _GLOBAL(ret_from_except_lite)
 	li	r10,MSR_RI
 	mtmsrd	r10,1		  /* Update machine state */
 #endif /* CONFIG_PPC_BOOK3E */
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */
 
 	.globl	fast_exc_return_irq
 fast_exc_return_irq:
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 82f43535e6867..23d2f20be4f2e 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -252,14 +252,19 @@  NOKPROBE_SYMBOL(oops_end);
 
 static int __die(const char *str, struct pt_regs *regs, long err)
 {
+	const char *pr = "";
+
 	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
 
+	if (IS_ENABLED(CONFIG_PREEMPTION))
+		pr = IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : " PREEMPT";
+
 	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n",
 	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
 	       PAGE_SIZE / 1024,
 	       early_radix_enabled() ? " MMU=Radix" : "",
 	       early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ? " MMU=Hash" : "",
-	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
+	       pr,
 	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
 	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
 	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",