From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tang Chen <tangchen@cn.fujitsu.com>
Date: Wed, 26 Dec 2012 02:49:27 +0000
Subject: Re: [PATCH v5 08/14] memory-hotplug: Common APIs to support page tables hot-remove
Message-Id: <50DA65B7.2050707@cn.fujitsu.com>
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References: <1356350964-13437-1-git-send-email-tangchen@cn.fujitsu.com> <1356350964-13437-9-git-send-email-tangchen@cn.fujitsu.com> <50D96116.1070305@huawei.com>
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To: Jianguo Wu <wujianguo@huawei.com>
Cc: akpm@linux-foundation.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, wency@cn.fujitsu.com, hpa@zytor.com, linfeng@cn.fujitsu.com, laijs@cn.fujitsu.com, mgorman@suse.de, yinghai@kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org

On 12/25/2012 04:17 PM, Jianguo Wu wrote:
>> +
>> +static void __meminit free_pagetable(struct page *page, int order)
>> +{
>> +	struct zone *zone;
>> +	bool bootmem = false;
>> +	unsigned long magic;
>> +
>> +	/* bootmem page has reserved flag */
>> +	if (PageReserved(page)) {
>> +		__ClearPageReserved(page);
>> +		bootmem = true;
>> +
>> +		magic = (unsigned long)page->lru.next;
>> +		if (magic = SECTION_INFO || magic = MIX_SECTION_INFO)
>> +			put_page_bootmem(page);
>
> Hi Tang,
>
> For removing memmap of sparse-vmemmap, in cpu_has_pse case, if magic = SECTION_INFO,
> the order will be get_order(PMD_SIZE), so we need a loop here to put all the 512 pages.
>
Hi Wu,

Thanks for reminding me that. I truely missed it.

And since in register_page_bootmem_info_section(), a whole memory
section will be set as SECTION_INFO, I think we don't need to check
the page magic one by one, just the first one is enough. :)

I will fix it, thanks. :)