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Date: Fri, 18 Jan 2013 15:58:27 +0800
From: Lin Feng <linfeng@cn.fujitsu.com>
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To: Michal Hocko <mhocko@suse.cz>
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Subject: Re: [PATCH v3 1/2] memory-hotplug: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE
 and revert register_page_bootmem_info_node() when platform not support
References: <1358324059-9608-1-git-send-email-linfeng@cn.fujitsu.com> <1358324059-9608-2-git-send-email-linfeng@cn.fujitsu.com> <20130116141436.GE343@dhcp22.suse.cz> <50F7D456.9000904@cn.fujitsu.com> <20130117130509.GE20538@dhcp22.suse.cz>
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Hi Michal,

On 01/17/2013 09:05 PM, Michal Hocko wrote:
> On Thu 17-01-13 18:37:10, Lin Feng wrote:
> [...]
>>> > > I am still not sure I understand the relation to MEMORY_HOTREMOVE.
>>> > > Is register_page_bootmem_info_node required/helpful even if
>>> > > !CONFIG_MEMORY_HOTREMOVE?
>> > From old kenrel's view register_page_bootmem_info_node() is defined in 
>> > CONFIG_MEMORY_HOTPLUG_SPARSE, it registers some info for 
>> > memory hotplug/remove. If we don't use MEMORY_HOTPLUG feature, this
>> > function is empty, we don't need the info at all.
>> > So this info is not required/helpful if !CONFIG_MEMORY_HOTREMOVE.
> OK, then I suggest moving it under CONFIG_MEMORY_HOTREMOVE guards rather
> than CONFIG_MEMORY_HOTPLUG.
I can't agree more ;-) 
I also find that page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG
is also such case, I fix it by the way.

thanks,
linfeng
>