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From:   Thomas Gleixner <tglx@linutronix.de>
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To:     Huacai Chen <chenhuacai@gmail.com>
Cc:     Marc Zyngier <maz@kernel.org>,
        Huacai Chen <chenhuacai@loongson.cn>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: Re: [PATCH 1/2] genirq/msi, platform-msi: Adjust return value of
 msi_domain_prepare_irqs()
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Date:   Tue, 30 May 2023 14:22:27 +0200
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On Tue, May 30 2023 at 16:34, Huacai Chen wrote:
> On Tue, May 30, 2023 at 4:19=E2=80=AFAM Thomas Gleixner <tglx@linutronix.=
de> wrote:
>> Now take that number and divide it by the number of devices on the bus
>> and you get at least a sensible limit which does not immediately cause
>> vector exhaustion.
>>
>> That limit might be suboptimal if there are lots of other devices on
>> that bus which just require one or two vectors, but that's something
>> which can be optimized via a generic command line option or even a sysfs
>> mechanism.
> Hmm, if we still use the command line, then we still have some similar
> drawbacks.

Only for optimization. Without the optimization the limit might end up
being overbroad, but it definitely prevents vector exhaustion. For quite
some cases this might be even the proper limit which does not need any
further tweaking.

Thanks,

        tglx