Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages() and reset_node_managed_pages() in hotadd_new_pgdat()

From	Tang Chen <tangchen@cn.fujitsu.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages() and reset_node_managed_pages() in hotadd_new_pgdat()
Date	2015-08-26 09:30 +0200
Message-ID	<q1DjI-7nv-17@gated-at.bofh.it> (permalink)
References	(1 earlier) <pWck9-6P2-5@gated-at.bofh.it> <q0AQW-6D0-1@gated-at.bofh.it> <q0W57-3om-67@gated-at.bofh.it> <q0Wy6-3WH-17@gated-at.bofh.it> <q0Y6S-6gu-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 08/24/2015 07:24 PM, Xishi Qiu wrote:
> ......
>>>> [ 2007.584000] On node 5 totalpages: 0
>>>> [ 2007.585000] Built 5 zonelists in Node order, mobility grouping on.  Total pages: 32588823
>>>> [ 2007.594000] Policy zone: Normal
>>>> [ 2007.598000] init_memory_mapping: [mem 0x60000000000-0x607ffffffff]
>>>>
>>>>
>>>> And also, if we merge this patch, /sys/devices/system/node/nodeX/meminfo will break.
>>>>
>>> trigger call trace?
>> No. There is no error output. But if you see /sys/devices/system/node/nodeX/meminfo,
>> memory size will double because totalpages is calculated once here, and one more time
>> when onlining memory.
>>
> Hi Tang,
>
> Do you mean si_meminfo_node() -> val->totalram = managed_pages; will be added double?
> But my patch will keep it 0 in hotadd_new_pgdat(), so it will not be double, right?
>

Hi,

I mean this:

online_pages()
|--> zone->zone_pgdat->node_present_pages += onlined_pages;

It will be double.

Since meminfo data is retrieved from these kernel structures, /proc/meminfo
will be broken.


Actually speaking, reset it when hot-adding memory is not a good idea.
We should make the memory init code be suitable for both boot code and
memory hot-plug code.


Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages()  and reset_node_managed_pages() in hotadd_new_pgdat() Tang Chen <tangchen@cn.fujitsu.com> - 2015-08-23 12:40 +0200
  Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages()  and reset_node_managed_pages() in hotadd_new_pgdat() Xishi Qiu <qiuxishi@huawei.com> - 2015-08-24 11:20 +0200
    Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages()  and reset_node_managed_pages() in hotadd_new_pgdat() Tang Chen <tangchen@cn.fujitsu.com> - 2015-08-24 11:50 +0200
      Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages()  and reset_node_managed_pages() in hotadd_new_pgdat() Xishi Qiu <qiuxishi@huawei.com> - 2015-08-24 13:30 +0200
        Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages()  and reset_node_managed_pages() in hotadd_new_pgdat() Tang Chen <tangchen@cn.fujitsu.com> - 2015-08-26 09:30 +0200

csiph-web