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Subject: Re: [PATCH] arm64: Kconfig: Increase NR_CPUS default to 512
To:     Vanshidhar Konda <vanshikonda@os.amperecomputing.com>,
        Will Deacon <will@kernel.org>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        catalin.marinas@arm.com, patches@amperecomputing.com
References: <20210110053615.3594358-1-vanshikonda@os.amperecomputing.com>
 <20210111105636.GA7071@willie-the-truck>
 <20210111175741.ldifmv7uhdekbq5d@con01sys-r111.scc-lab.amperecomputing.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <fb9542df-19cf-4db7-d112-0917e5b65e9f@infradead.org>
Date:   Mon, 11 Jan 2021 10:03:18 -0800
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On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
> On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
>> On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
>>> From: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
>>>
>>> Increase the default value of NR_CPUS to 512 from 256. This will
>>> enable the defconfig kernel to support platforms that have upto
>>> 512 cores.
>>
>> Do we already support such a platform, and what is it? I'm fine with bumping.
>> the number, it's just nice to be able to say specifically _why_ we're dong
>> it.
> 
> I'm not aware of any publicly available systems that run into the 256
> core limitation. At Ampere we have internal systems that would benefit
> from this change as they support more than 256 cores.

But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.

-- 
~Randy