linux-kernel - Re: [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <50501B9C.7000200@cn.fujitsu.com>
Date:	Wed, 12 Sep 2012 13:20:28 +0800
From:	Wen Congyang <wency@...fujitsu.com>
To:	Vasilis Liaskovitis <vasilis.liaskovitis@...fitbricks.com>
CC:	Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>,
	Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org, linux-acpi@...r.kernel.org,
	linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
	linux-ia64@...r.kernel.org, cmetcalf@...era.com,
	sparclinux@...r.kernel.org, rientjes@...gle.com, liuj97@...il.com,
	len.brown@...el.com, benh@...nel.crashing.org, paulus@...ba.org,
	cl@...ux.com, minchan.kim@...il.com, kosaki.motohiro@...fujitsu.com
Subject: Re: [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory

At 09/10/2012 09:52 PM, Vasilis Liaskovitis Wrote:
> Hi,
> 
> On Mon, Sep 10, 2012 at 10:01:44AM +0800, Wen Congyang wrote:
>> At 09/10/2012 09:46 AM, Yasuaki Ishimatsu Wrote:
>>> Hi Wen,
>>>
>>> 2012/09/01 5:49, Andrew Morton wrote:
>>>> On Tue, 28 Aug 2012 18:00:07 +0800
>>>> wency@...fujitsu.com wrote:
>>>>
>>>>> This patch series aims to support physical memory hot-remove.
>>>>
>>>> I doubt if many people have hardware which permits physical memory
>>>> removal?  How would you suggest that people with regular hardware can
>>>> test these chagnes?
>>>
>>> How do you test the patch? As Andrew says, for hot-removing memory,
>>> we need a particular hardware. I think so too. So many people may want
>>> to know how to test the patch.
>>> If we apply following patch to kvm guest, can we hot-remove memory on
>>> kvm guest?
>>>
>>> http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01389.html
>>
>> Yes, if we apply this patchset, we can test hot-remove memory on kvm guest.
>> But that patchset doesn't implement _PS3, so there is some restriction.
> 
> the following repos contain the patchset above, plus 2 more patches that add
> PS3 support to the dimm devices in qemu/seabios:
> 
> https://github.com/vliaskov/seabios/commits/memhp-v2
> https://github.com/vliaskov/qemu-kvm/commits/memhp-v2
> 
> I have not posted the PS3 patches yet in the qemu list, but will post them
> soon for v3 of the memory hotplug series. If you have issues testing, let me
> know.

Hmm, seabios doesn't support ACPI table SLIT. We can specify node it for dimm
device, so I think we should support SLIT in seabios. Otherwise we may meet
the following kernel messages:
[  325.016769] init_memory_mapping: [mem 0x40000000-0x5fffffff]
[  325.018060]  [mem 0x40000000-0x5fffffff] page 2M
[  325.019168] [ffffea0001000000-ffffea00011fffff] potential offnode page_structs
[  325.024172] [ffffea0001200000-ffffea00013fffff] potential offnode page_structs
[  325.028596]  [ffffea0001400000-ffffea00017fffff] PMD -> [ffff880035000000-ffff8800353fffff] on node 1
[  325.031775] [ffffea0001600000-ffffea00017fffff] potential offnode page_structs

Do you have plan to do it?

Thanks
Wen Congyang

> 
> thanks,
> 
> - Vasilis
> 

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