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Subject: Re: [PATCH 1/2] genirq: add an affinity parameter to
 irq_create_mapping()
To:     Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org
Cc:     Paul Mackerras <paulus@samba.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        linux-block@vger.kernel.org,
        "Michael S . Tsirkin" <mst@redhat.com>,
        Marc Zyngier <maz@kernel.org>, linuxppc-dev@lists.ozlabs.org,
        linux-pci@vger.kernel.org, Christoph Hellwig <hch@lst.de>
References: <20201124200308.1110744-1-lvivier@redhat.com>
 <20201124200308.1110744-2-lvivier@redhat.com>
 <87h7pel7ng.fsf@nanos.tec.linutronix.de>
From:   Laurent Vivier <lvivier@redhat.com>
Message-ID: <8e9002d0-086f-1e7d-4b94-45b6d49f7917@redhat.com>
Date:   Wed, 25 Nov 2020 08:30:05 +0100
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On 24/11/2020 23:19, Thomas Gleixner wrote:
> On Tue, Nov 24 2020 at 21:03, Laurent Vivier wrote:
>> This parameter is needed to pass it to irq_domain_alloc_descs().
>>
>> This seems to have been missed by
>> o06ee6d571f0e ("genirq: Add affinity hint to irq allocation")
> 
> No, this has not been missed at all. There was and is no reason to do
> this.
> 
>> This is needed to implement proper support for multiqueue with
>> pseries.
> 
> And because pseries needs this _all_ callers need to be changed?
> 
>>  123 files changed, 171 insertions(+), 146 deletions(-)
> 
> Lots of churn for nothing. 99% of the callers will never need that.
> 
> What's wrong with simply adding an interface which takes that parameter,
> make the existing one an inline wrapper and and leave the rest alone?

Nothing. I'm going to do like that.

Thank you for your comment.

Laurent