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Message-ID: <dbb07298-a474-f67c-dcd1-64fbf2aae91e@huawei.com>
Date:   Tue, 18 Oct 2022 09:22:38 +0800
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Subject: Re: [PATCH -next] genirq: Add SPARSE_NR_IRQS Kconfig option
To:     <tglx@linutronix.de>, <linux-kernel@vger.kernel.org>
References: <20220930085839.315461-1-chenlifu@huawei.com>
From:   chenlifu <chenlifu@huawei.com>
In-Reply-To: <20220930085839.315461-1-chenlifu@huawei.com>
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在 2022/9/30 16:58, Chen Lifu 写道:
> On a large-scale multi-core and NUMA platform, more than 1024 cores and
> 16 NUMA nodes for example, even if SPASE_IRQ is selected to increase the
> number of interrupt numbers by 8196 base on NR_IRQS, the interrupt numbers
> requirement cannot be met. Therefore, make the number of sparse interrupt
> numbers configurable.
> 
> Signed-off-by: Chen Lifu <chenlifu@huawei.com>
> ---
>   kernel/irq/Kconfig     | 8 ++++++++
>   kernel/irq/internals.h | 2 +-
>   2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
> index db3d174c53d4..b517b820e329 100644
> --- a/kernel/irq/Kconfig
> +++ b/kernel/irq/Kconfig
> @@ -123,10 +123,18 @@ config SPARSE_IRQ
>   	  ( Sparse irqs can also be beneficial on NUMA boxes, as they spread
>   	    out the interrupt descriptors in a more NUMA-friendly way. )
>   
>   	  If you don't know what to do here, say N.
>   
> +config SPARSE_NR_IRQS
> +	int "Number of sparse interrupt numbers"
> +	depends on SPARSE_IRQ
> +	default 8196
> +	help
> +	  This defines the maximum number of interrupt numbers
> +	  that can be dynamically expanded.
> +
>   config GENERIC_IRQ_DEBUGFS
>   	bool "Expose irq internals in debugfs"
>   	depends on DEBUG_FS
>   	select GENERIC_IRQ_INJECTION
>   	default n
> diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
> index f09c60393e55..ab8ac93c60e6 100644
> --- a/kernel/irq/internals.h
> +++ b/kernel/irq/internals.h
> @@ -10,11 +10,11 @@
>   #include <linux/kernel_stat.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/sched/clock.h>
>   
>   #ifdef CONFIG_SPARSE_IRQ
> -# define IRQ_BITMAP_BITS	(NR_IRQS + 8196)
> +# define IRQ_BITMAP_BITS	(NR_IRQS + CONFIG_SPARSE_NR_IRQS)
>   #else
>   # define IRQ_BITMAP_BITS	NR_IRQS
>   #endif
>   
>   #define istate core_internal_state__do_not_mess_with_it

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