From: Andrew Morton <akpm@linux-foundation.org>
To: wency@cn.fujitsu.com
Cc: 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, 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
Subject: Re: [RFC v8 PATCH 13/20] memory-hotplug: check page type in get_page_bootmem
Date: Fri, 31 Aug 2012 14:30:32 -0700 [thread overview]
Message-ID: <20120831143032.1343e99a.akpm@linux-foundation.org> (raw)
In-Reply-To: <1346148027-24468-14-git-send-email-wency@cn.fujitsu.com>
On Tue, 28 Aug 2012 18:00:20 +0800
wency@cn.fujitsu.com wrote:
> From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> There is a possibility that get_page_bootmem() is called to the same page many
> times. So when get_page_bootmem is called to the same page, the function only
> increments page->_count.
I really don't understand this explanation, even after having looked at
the code. Can you please have another attempt at the changelog?
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -95,10 +95,17 @@ static void release_memory_resource(struct resource *res)
> static void get_page_bootmem(unsigned long info, struct page *page,
> unsigned long type)
> {
> - page->lru.next = (struct list_head *) type;
> - SetPagePrivate(page);
> - set_page_private(page, info);
> - atomic_inc(&page->_count);
> + unsigned long page_type;
> +
> + page_type = (unsigned long) page->lru.next;
> + if (page_type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
> + page_type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE){
> + page->lru.next = (struct list_head *) type;
> + SetPagePrivate(page);
> + set_page_private(page, info);
> + atomic_inc(&page->_count);
> + } else
> + atomic_inc(&page->_count);
> }
And a code comment which explains what is going on would be good. As
is always the case ;)
next prev parent reply other threads:[~2012-08-31 21:30 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-28 10:00 [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory wency
2012-08-28 10:00 ` [RFC v8 PATCH 01/20] memory-hotplug: rename remove_memory() to offline_memory()/offline_pages() wency
2012-08-28 10:00 ` [RFC v8 PATCH 02/20] memory-hotplug: implement offline_memory() wency
2012-08-28 10:00 ` [RFC v8 PATCH 03/20] memory-hotplug: store the node id in acpi_memory_device wency
2012-08-28 10:00 ` [RFC v8 PATCH 04/20] memory-hotplug: offline and remove memory when removing the memory device wency
2012-08-31 20:55 ` Andrew Morton
2012-09-03 1:30 ` Wen Congyang
2012-08-28 10:00 ` [RFC v8 PATCH 05/20] memory-hotplug: check whether memory is present or not wency
2012-08-28 10:00 ` [RFC v8 PATCH 06/20] memory-hotplug: export the function acpi_bus_remove() wency
2012-08-28 10:00 ` [RFC v8 PATCH 07/20] memory-hotplug: call acpi_bus_remove() to remove memory device wency
2012-08-28 10:00 ` [RFC v8 PATCH 08/20] memory-hotplug: remove /sys/firmware/memmap/X sysfs wency
2012-08-31 21:06 ` Andrew Morton
2012-09-03 5:51 ` Wen Congyang
2012-09-04 23:16 ` Andrew Morton
2012-09-05 1:41 ` Wen Congyang
2012-09-03 7:31 ` Wen Congyang
2012-08-28 10:00 ` [RFC v8 PATCH 09/20] memory-hotplug: does not release memory region in PAGES_PER_SECTION chunks wency
2012-08-28 10:00 ` [RFC v8 PATCH 10/20] memory-hotplug: add memory_block_release wency
2012-08-28 10:00 ` [RFC v8 PATCH 11/20] memory-hotplug: remove_memory calls __remove_pages wency
2012-08-28 10:00 ` [RFC v8 PATCH 12/20] memory-hotplug: introduce new function arch_remove_memory() wency
2012-08-28 10:00 ` [RFC v8 PATCH 13/20] memory-hotplug: check page type in get_page_bootmem wency
2012-08-31 21:30 ` Andrew Morton [this message]
2012-09-04 3:46 ` Wen Congyang
2012-09-04 9:54 ` Yasuaki Ishimatsu
2012-08-28 10:00 ` [RFC v8 PATCH 14/20] memory-hotplug: move register_page_bootmem_info_node and put_page_bootmem for sparse-vmemmap wency
2012-08-28 10:00 ` [RFC v8 PATCH 15/20] memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap wency
2012-08-28 10:00 ` [RFC v8 PATCH 16/20] memory-hotplug: free memmap " wency
2012-08-28 10:00 ` [RFC v8 PATCH 17/20] memory_hotplug: clear zone when the memory is removed wency
2012-08-28 10:00 ` [RFC v8 PATCH 18/20] memory-hotplug: add node_device_release wency
2012-08-28 10:00 ` [RFC v8 PATCH 19/20] memory-hotplug: remove sysfs file of node wency
2012-08-28 10:00 ` [RFC v8 PATCH 20/20] memory-hotplug: clear hwpoisoned flag when onlining pages wency
2012-08-31 20:49 ` [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory Andrew Morton
2012-09-10 1:46 ` Yasuaki Ishimatsu
2012-09-10 2:01 ` Wen Congyang
2012-09-10 13:52 ` Vasilis Liaskovitis
[not found] ` <CAAV+Mu7YWRWnxt78F4ZDMrrUsWB=n-_qkYOcQT7WQ2HwP89Obw@mail.gmail.com>
2012-09-11 1:23 ` Minchan Kim
[not found] ` <CAAV+Mu4hb0qbW2Ry6w5FAGUM06puDH0v_H-jr584-G9CzJqSGw@mail.gmail.com>
2012-09-11 5:39 ` Wen Congyang
2012-09-12 6:17 ` Minchan Kim
2012-09-11 1:25 ` Wen Congyang
2012-09-12 5:20 ` Wen Congyang
2012-09-12 17:18 ` Vasilis Liaskovitis
2012-09-18 9:39 ` Wen Congyang
2012-09-19 17:02 ` Vasilis Liaskovitis
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