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Subject: Re: [PATCH 1/5] x86/smpboot: Add the missing description of
 possible_cpus
To:     Peter Zijlstra <peterz@infradead.org>
CC:     <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
        <linux-acpi@vger.kernel.org>, <linux-doc@vger.kernel.org>,
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References: <20180320110432.28127-1-douly.fnst@cn.fujitsu.com>
 <20180320110432.28127-2-douly.fnst@cn.fujitsu.com>
 <20180320123712.GR4043@hirez.programming.kicks-ass.net>
From:   Dou Liyang <douly.fnst@cn.fujitsu.com>
Message-ID: <f64cb207-3851-9a26-2001-653fc0068540@cn.fujitsu.com>
Date:   Wed, 21 Mar 2018 13:33:24 +0800
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Hi Peter,

At 03/20/2018 08:37 PM, Peter Zijlstra wrote:
> On Tue, Mar 20, 2018 at 07:04:28PM +0800, Dou Liyang wrote:
> 
>> +	possible_cpus=	[s390,x86_64] Use this to set hotpluggable cpus.
>> +			This option sets possible_cpus bits in cpu_possible_map.
>> +			Thus keeping the numbers of bits set constant even if
>> +			the machine gets rebooted.
> 
> That description, esp. the last sentence, doesn't make any kind of sense
> to me. What?
> 

Ah, sure enough, I can't be lazy. :-) I stole that from the commit
   3b11ce7f542e ("x86: use possible_cpus=NUM to extend the possible cpus 
allowed")

How about:

possible_cpus=	[s390,x86_64] Set the number of possible CPUs which
		are determined by the ACPI tables MADT or mptables by
		default. possible_cpus=n : n >= 1 enforces the possible
		number to be 'n'.
		While nr_cpus is also be set: nr_cpus=m, choice the
		minimum one for the number of possible CPUs.

Thank,
	dou