From: Michael Ellerman <mpe@ellerman•id.au>
To: Christophe Leroy <christophe.leroy@c-s•fr>,
Sebastian Andrzej Siewior <bigeasy@linutronix•de>,
linux-kernel@vger•kernel.org
Cc: Paul Mackerras <paulus@samba•org>,
tglx@linutronix•de, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 03/34] powerpc: Use CONFIG_PREEMPTION
Date: Wed, 16 Oct 2019 20:33:08 +1100 [thread overview]
Message-ID: <87d0ext4q3.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <156db456-af80-1f5e-6234-2e78283569b6@c-s.fr>
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
next prev parent reply other threads:[~2019-10-16 9:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191015191821.11479-1-bigeasy@linutronix.de>
2019-10-15 19:17 ` [PATCH 03/34] powerpc: Use CONFIG_PREEMPTION Sebastian Andrzej Siewior
2019-10-16 4:57 ` Christophe Leroy
2019-10-16 7:48 ` Sebastian Andrzej Siewior
2019-10-16 9:33 ` Michael Ellerman [this message]
2019-10-16 9:35 ` Sebastian Andrzej Siewior
2019-10-24 13:59 ` [PATCH 03/34 v2] " Sebastian Andrzej Siewior
2019-10-24 16:04 ` [PATCH 03/34 v3] " Sebastian Andrzej Siewior
2019-11-12 12:38 ` Michael Ellerman
2019-12-08 14:58 ` [tip: sched/urgent] sched/rt, " tip-bot2 for Thomas Gleixner
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