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From:   Jakub Sitnicki <jakub@cloudflare.com>
To:     virtualization@lists.linux-foundation.org
Cc:     "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        linux-kernel@vger.kernel.org, kernel-team@cloudflare.com
Subject: Re: [PATCH v2] virtio_pci: Switch away from deprecated
 irq_set_affinity_hint
Date:   Thu, 26 Oct 2023 18:25:08 +0200
In-reply-to: <20231025145319.380775-1-jakub@cloudflare.com>
Message-ID: <87wmv91h3p.fsf@cloudflare.com>
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On Wed, Oct 25, 2023 at 04:53 PM +02, Jakub Sitnicki wrote:
> Since commit 65c7cdedeb30 ("genirq: Provide new interfaces for affinity
> hints") irq_set_affinity_hint is being phased out.
>
> Switch to new interfaces for setting and applying irq affinity hints.
>
> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
> ---
> v2:
>  - Leave cpumask_copy as is. We can't pass pointer to stack memory as hint.
>    Proposed a change to IRQ affinity interface to address this limitation:
>    https://lore.kernel.org/r/20231025141517.375378-1-jakub@cloudflare.com

Just a note to the ^ - if we wanted to get rid of msix_affinity_masks,
we could call irq_set_affinity directly, instead of calling it through
irq_set_affinity[_and]_hint.

The hint wouldn't be available any more in /proc/irq/N/affinity_hint,
but the same information can be gathered from /proc/irq/N/smp_affinity.

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