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Subject: Re: [PATCH] genirq: Make sure the affinity to be set is not empty
To:     tglx@linutronix.de
Cc:     linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org
References: <1545312957-8504-1-git-send-email-sramana@codeaurora.org>
From:   Srinivas Ramana <sramana@codeaurora.org>
Message-ID: <45756028-c96f-e3b5-389d-d8f022c59c5d@codeaurora.org>
Date:   Wed, 2 Jan 2019 12:29:33 +0530
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On 12/20/2018 7:05 PM, Srinivas Ramana wrote:
> If the default_affinity is managed/initialized by a system and
> all the cpus present in irq_default_affinity are hotplugged out
> we may end up passing a cpumask of 0 to irq_do_set_affinity().
> 
> Fix this by falling back to cpu_online_mask in case the
> calculated affinity becomes zero.
> 
> Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
> ---
>   kernel/irq/manage.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index 9dbdccab3b6a..5c0ba5ca5930 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -393,6 +393,9 @@ int irq_setup_affinity(struct irq_desc *desc)
>   	}
>   
>   	cpumask_and(&mask, cpu_online_mask, set);
> +	if (cpumask_empty(&mask))
> +		cpumask_copy(&mask, cpu_online_mask);
> +
>   	if (node != NUMA_NO_NODE) {
>   		const struct cpumask *nodemask = cpumask_of_node(node);
>   
> 

Hi,

Can you provide your feedback on this?

Thanks,
-- Srinivas R

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