linux-kernel - Re: [PATCH] kernel: x86: apic: Replace GFP_ATOMIC with GFP_KERNEL in __add_pin_to_irq

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Date:   Tue, 13 Feb 2018 16:56:04 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Jia-Ju Bai <baijiaju1990@...il.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        jgross@...e.com, douly.fnst@...fujitsu.com, kkamagui@...il.com,
        gregkh@...uxfoundation.org, mka@...omium.org,
        linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH] kernel: x86: apic: Replace GFP_ATOMIC with GFP_KERNEL in
 __add_pin_to_irq_node


* Jia-Ju Bai <baijiaju1990@...il.com> wrote:

> The function __add_pin_to_irq_node is not called in atomic context.
> Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@...il.com>
> ---
>  arch/x86/kernel/apic/io_apic.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index 201579d..665c013 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -379,7 +379,7 @@ static int __add_pin_to_irq_node(struct mp_chip_data *data,
>  		if (entry->apic == apic && entry->pin == pin)
>  			return 0;
>  
> -	entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_ATOMIC, node);
> +	entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_KERNEL, node);
>  	if (!entry) {
>  		pr_err("can not alloc irq_pin_list (%d,%d,%d)\n",
>  		       node, apic, pin);

NAK: this is called in an atomic section: with IRQs disabled ...

Thanks,

	Ingo