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Date: Tue, 12 Jan 2010 16:05:13 -0800
From: Yinghai Lu <yinghai@kernel.org>
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To: Suresh Siddha <suresh.b.siddha@intel.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>,
       "ananth@in.ibm.com" <ananth@in.ibm.com>, Ingo Molnar <mingo@elte.hu>,
       Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -v2 5/5] x86: use dmi check to treat disabled cpus as
 hotplug cpus.
References: <1263338274-6485-1-git-send-email-yinghai@kernel.org>	 <1263338274-6485-5-git-send-email-yinghai@kernel.org> <1263340563.2854.1011.camel@sbs-t61.sc.intel.com>
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On 01/12/2010 03:56 PM, Suresh Siddha wrote:
> On Tue, 2010-01-12 at 15:17 -0800, Yinghai Lu wrote:
>> some systems that have disable cpus entries because same
>>   BIOS will support 2 sockets and 4 sockets and more at
>>   same time, BIOS just leave some disable entries, but
>>   those system do not support cpu hotplug. we don't need
>>   treat disabled_cpus as hotplug cpus.
>> so we can make nr_cpu_ids smaller and save more space
>>   (pcpu data allocations), and could make some systems run
>>   with logical flat instead of physical flat apic mode
>>
>> -v2: change to black list instead
> 
> I don't think this list will work because every HT system with HT
> disabled in the bios shows that logical cpu as disabled.

so you want to treat those disabled cpus in the those system as hotplug cpus or not?

YH