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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Jakub Sitnicki <jakub@cloudflare.com>
Cc:     linux-kernel@vger.kernel.org, kernel-team@cloudflare.com,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Subject: Re: [PATCH] genirq: Own affinity hint
In-Reply-To: <20231025141517.375378-1-jakub@cloudflare.com>
References: <20231025141517.375378-1-jakub@cloudflare.com>
Date:   Wed, 25 Oct 2023 22:10:41 +0200
Message-ID: <878r7q5upq.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Wed, Oct 25 2023 at 16:15, Jakub Sitnicki wrote:
> @@ -55,26 +55,33 @@ static int alloc_masks(struct irq_desc *desc, int node)
>  {
>  	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
>  				     GFP_KERNEL, node))
> -		return -ENOMEM;
> +		goto err_affinity;
> +	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity_hint,
> +				     GFP_KERNEL, node))

This gets allocated for every interrupt descriptor but only a few or
even none will ever use it. Seriously no.

> +		goto err_affinity_hint;
>  
>  #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
>  	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
> -				     GFP_KERNEL, node)) {
> -		free_cpumask_var(desc->irq_common_data.affinity);
> -		return -ENOMEM;
> -	}
> +				     GFP_KERNEL, node))
> +		goto err_effective_affinity;
>  #endif
>  
>  #ifdef CONFIG_GENERIC_PENDING_IRQ
> -	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
> -#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
> -		free_cpumask_var(desc->irq_common_data.effective_affinity);
> -#endif
> -		free_cpumask_var(desc->irq_common_data.affinity);
> -		return -ENOMEM;
> -	}
> +	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node))
> +		goto err_pending_mask;
>  #endif
>  	return 0;
> +
> +err_pending_mask:

How is this supposed to compile with CONFIG_GENERIC_PENDING_IRQ=n ?

> +#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
> +	free_cpumask_var(desc->irq_common_data.effective_affinity);
> +#endif
> +err_effective_affinity:

and this with CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK=n ?

Thanks,

        tglx