From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/highmem: change BUG_ON() to WARN_ON()
Date: Thu, 21 Mar 2019 07:00:04 +0100 [thread overview]
Message-ID: <9048ba12-a014-3ebe-c414-26f87401c758@c-s.fr> (raw)
In-Reply-To: <87va0c23s8.fsf@concordia.ellerman.id.au>
Le 21/03/2019 à 06:29, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>> In arch/powerpc/mm/highmem.c, BUG_ON() is called only when
>> CONFIG_DEBUG_HIGHMEM is selected, this means the BUG_ON() is
>> not vital and can be replaced by a a WARN_ON
>>
>> At the sametime, use IS_ENABLED() instead of #ifdef to clean a bit.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>> arch/powerpc/mm/highmem.c | 12 ++++--------
>> 1 file changed, 4 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
>> index 82a0e37557a5..b68c9f20fbdf 100644
>> --- a/arch/powerpc/mm/highmem.c
>> +++ b/arch/powerpc/mm/highmem.c
>> @@ -56,7 +54,7 @@ EXPORT_SYMBOL(kmap_atomic_prot);
>> void __kunmap_atomic(void *kvaddr)
>> {
>> unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
>> - int type __maybe_unused;
>> + int type;
>
> Why don't we move type into the block below.
Yes you're right, when Mathieu introduced the __maybe_unused, I was
wrongly thinging that kmap_atomic_idx() was doing something important
that had to be done also when DEBUG was not selected, but indeed it does
nothing else than returning the type.
I'll send a new patch.
Christophe
>
> eg:
>
>> @@ -66,12 +64,11 @@ void __kunmap_atomic(void *kvaddr)
>>
> - type = kmap_atomic_idx();
>>
>> -#ifdef CONFIG_DEBUG_HIGHMEM
>> - {
>> + if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
> int type = kmap_atomic_idx();
>> unsigned int idx;
>>
>> idx = type + KM_TYPE_NR * smp_processor_id();
>> - BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
>> + WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
>
>
> cheers
>
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/highmem: change BUG_ON() to WARN_ON()
Date: Thu, 21 Mar 2019 07:00:04 +0100 [thread overview]
Message-ID: <9048ba12-a014-3ebe-c414-26f87401c758@c-s.fr> (raw)
In-Reply-To: <87va0c23s8.fsf@concordia.ellerman.id.au>
Le 21/03/2019 à 06:29, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>> In arch/powerpc/mm/highmem.c, BUG_ON() is called only when
>> CONFIG_DEBUG_HIGHMEM is selected, this means the BUG_ON() is
>> not vital and can be replaced by a a WARN_ON
>>
>> At the sametime, use IS_ENABLED() instead of #ifdef to clean a bit.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>> arch/powerpc/mm/highmem.c | 12 ++++--------
>> 1 file changed, 4 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
>> index 82a0e37557a5..b68c9f20fbdf 100644
>> --- a/arch/powerpc/mm/highmem.c
>> +++ b/arch/powerpc/mm/highmem.c
>> @@ -56,7 +54,7 @@ EXPORT_SYMBOL(kmap_atomic_prot);
>> void __kunmap_atomic(void *kvaddr)
>> {
>> unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
>> - int type __maybe_unused;
>> + int type;
>
> Why don't we move type into the block below.
Yes you're right, when Mathieu introduced the __maybe_unused, I was
wrongly thinging that kmap_atomic_idx() was doing something important
that had to be done also when DEBUG was not selected, but indeed it does
nothing else than returning the type.
I'll send a new patch.
Christophe
>
> eg:
>
>> @@ -66,12 +64,11 @@ void __kunmap_atomic(void *kvaddr)
>>
> - type = kmap_atomic_idx();
>>
>> -#ifdef CONFIG_DEBUG_HIGHMEM
>> - {
>> + if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
> int type = kmap_atomic_idx();
>> unsigned int idx;
>>
>> idx = type + KM_TYPE_NR * smp_processor_id();
>> - BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
>> + WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
>
>
> cheers
>
next prev parent reply other threads:[~2019-03-21 6:00 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-07 9:47 [PATCH] powerpc/highmem: change BUG_ON() to WARN_ON() Christophe Leroy
2019-03-07 9:47 ` Christophe Leroy
2019-03-21 5:29 ` Michael Ellerman
2019-03-21 5:29 ` Michael Ellerman
2019-03-21 6:00 ` Christophe Leroy [this message]
2019-03-21 6:00 ` Christophe Leroy
2019-03-21 10:07 ` Michael Ellerman
2019-03-21 10:07 ` Michael Ellerman
2019-03-21 10:14 ` Christophe Leroy
2019-03-21 10:14 ` Christophe Leroy
2019-04-21 14:18 ` Michael Ellerman
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