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From: jszhang@marvell.com (Jisheng Zhang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] arm64: cpuidle: add __init section marker to arm_cpuidle_init
Date: Thu, 2 Jul 2015 12:58:49 +0800	[thread overview]
Message-ID: <20150702125849.67160aa9@xhacker> (raw)
In-Reply-To: <CAJKOXPceoV2jk=Go+ZoJZbP1MXx-HDLJpCFK9mrR9JLRU4x8Bg@mail.gmail.com>

Dear Krzysztof,

On Thu, 2 Jul 2015 12:59:44 +0900
Krzysztof Kozlowski <k.kozlowski@samsung.com> wrote:

> 2015-07-02 11:14 GMT+09:00 Jisheng Zhang <jszhang@marvell.com>:
> > It is not needed after booting, this patch moves the arm_cpuidle_init()
> > function to the __init section.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > ---
> >  arch/arm64/include/asm/cpuidle.h | 2 +-
> >  arch/arm64/kernel/cpuidle.c      | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
> > index 0f74f05..5748d3b 100644
> > --- a/arch/arm64/include/asm/cpuidle.h
> > +++ b/arch/arm64/include/asm/cpuidle.h
> > @@ -4,7 +4,7 @@
> >  #include <asm/proc-fns.h>
> >
> >  #ifdef CONFIG_CPU_IDLE
> > -extern int arm_cpuidle_init(unsigned int cpu);
> > +extern int __init arm_cpuidle_init(unsigned int cpu);
> 
> No, not here but...
> 
> >  extern int arm_cpuidle_suspend(int index);
> >  #else
> >  static inline int arm_cpuidle_init(unsigned int cpu)
> 
> ... here so the stub for !CONFIG_CPU_IDLE would be marked as well.

when !CONFIG_CPU_IDLE, arm_cpuidle_init() is inlined, and just return -EOPNOTSUPP;
Per my understanding, it will be optimized out by compiler. I'm not sure whether
there is any benefit to mark inlined function as __init. But Per my check, all
other inlined functions in linux kernel have no __init. What do you think?

Thanks,
Jisheng

WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <jszhang@marvell.com>
To: Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	<catalin.marinas@arm.com>, <will.deacon@arm.com>,
	<lorenzo.pieralisi@arm.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] arm64: cpuidle: add __init section marker to arm_cpuidle_init
Date: Thu, 2 Jul 2015 12:58:49 +0800	[thread overview]
Message-ID: <20150702125849.67160aa9@xhacker> (raw)
In-Reply-To: <CAJKOXPceoV2jk=Go+ZoJZbP1MXx-HDLJpCFK9mrR9JLRU4x8Bg@mail.gmail.com>

Dear Krzysztof,

On Thu, 2 Jul 2015 12:59:44 +0900
Krzysztof Kozlowski <k.kozlowski@samsung.com> wrote:

> 2015-07-02 11:14 GMT+09:00 Jisheng Zhang <jszhang@marvell.com>:
> > It is not needed after booting, this patch moves the arm_cpuidle_init()
> > function to the __init section.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > ---
> >  arch/arm64/include/asm/cpuidle.h | 2 +-
> >  arch/arm64/kernel/cpuidle.c      | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
> > index 0f74f05..5748d3b 100644
> > --- a/arch/arm64/include/asm/cpuidle.h
> > +++ b/arch/arm64/include/asm/cpuidle.h
> > @@ -4,7 +4,7 @@
> >  #include <asm/proc-fns.h>
> >
> >  #ifdef CONFIG_CPU_IDLE
> > -extern int arm_cpuidle_init(unsigned int cpu);
> > +extern int __init arm_cpuidle_init(unsigned int cpu);
> 
> No, not here but...
> 
> >  extern int arm_cpuidle_suspend(int index);
> >  #else
> >  static inline int arm_cpuidle_init(unsigned int cpu)
> 
> ... here so the stub for !CONFIG_CPU_IDLE would be marked as well.

when !CONFIG_CPU_IDLE, arm_cpuidle_init() is inlined, and just return -EOPNOTSUPP;
Per my understanding, it will be optimized out by compiler. I'm not sure whether
there is any benefit to mark inlined function as __init. But Per my check, all
other inlined functions in linux kernel have no __init. What do you think?

Thanks,
Jisheng

  reply	other threads:[~2015-07-02  4:58 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-02  2:14 [PATCH v2] arm64: cpuidle: add __init section marker to arm_cpuidle_init Jisheng Zhang
2015-07-02  2:14 ` Jisheng Zhang
2015-07-02  3:59 ` Krzysztof Kozlowski
2015-07-02  3:59   ` Krzysztof Kozlowski
2015-07-02  4:58   ` Jisheng Zhang [this message]
2015-07-02  4:58     ` Jisheng Zhang
2015-07-02  5:23     ` Krzysztof Kozlowski
2015-07-02  5:23       ` Krzysztof Kozlowski

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