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From:   Huacai Chen <chenhuacai@gmail.com>
Date:   Thu, 1 Jun 2023 12:19:04 +0800
Message-ID: <CAAhV-H64NWn0gk6Y0gAHe+YUUuALPySgKPC1WR5faWihV_s5rQ@mail.gmail.com>
Subject: Re: [PATCH] pci: irq: Add an early parameter to limit pci irq numbers
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Huacai Chen <chenhuacai@loongson.cn>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Ahmed S . Darwish" <darwi@linutronix.de>,
        Kevin Tian <kevin.tian@intel.com>, linux-pci@vger.kernel.org,
        Jianmin Lv <lvjianmin@loongson.cn>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        loongson-kernel@lists.loongnix.cn,
        Juxin Gao <gaojuxin@loongson.cn>,
        Marc Zyngier <maz@kernel.org>, linux-kernel@vger.kernel.org
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Hi, Jason,

On Thu, Jun 1, 2023 at 3:14=E2=80=AFAM Jason Gunthorpe <jgg@ziepe.ca> wrote=
:
>
> On Mon, May 29, 2023 at 02:52:29PM +0800, Huacai Chen wrote:
>
> > > But IMO what you are proposing seems like usecase driven and may not =
work all
> > > the time due to architecture limitation. This again proves that the e=
xisting
> > > solution is sufficient enough.
>
> > Yes, it's a usecase driven solution, so I provide a cmdline parameter
> > to let the user decide.
>
> The NIC drivers should be consuming interrupts based on the number of
> queues they are using, and that is something you can control from the
> command line, eg ethtool IIRC. Usually it defaults to the number of
> CPUs.
>
> Basically, you want to enable the user to configure the system with a
> user specified reduced number of NIC queues, and we already have way
> to do that.
Yes, ethtool is a possible way, thank you very much.

Huacai
>
> Jason