From: Shaohui Zheng <shaohui.zheng@intel.com>
To: "Américo Wang" <xiyou.wangcong@gmail.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, haicheng.li@linux.intel.com,
lethal@linux-sh.org, ak@linux.intel.com,
shaohui.zheng@linux.intel.com,
Haicheng Li <haicheng.li@intel.com>
Subject: Re: [8/8,v3] NUMA Hotplug Emulator: documentation
Date: Tue, 23 Nov 2010 07:23:02 +0800 [thread overview]
Message-ID: <20101122232302.GA11727@shaohui> (raw)
In-Reply-To: <20101122160412.GE4137@hack>
On Tue, Nov 23, 2010 at 12:04:12AM +0800, Américo Wang wrote:
> On Mon, Nov 22, 2010 at 07:33:51AM +0800, Shaohui Zheng wrote:
> >On Sun, Nov 21, 2010 at 11:03:45PM +0800, Américo Wang wrote:
> >>
> >> >From your documentation above, it looks like you are trying
> >> to move one CPU between nodes?
> >Yes, you are correct. With cpu probe/release interface, you can hot-remove a
> >CPU from a node, and hot-add it to another node.
>
>
> Can I also move the CPU to another node _after_ it is hot-added?
> Or I have to hot-remove it first and then hot-add it again?
of course you can. you can hot-remove it via cpu/release interface, and then hot-add
it by cpu/probe interface.
With the cpu probe/reelase interface, we can design some stress test cases to hot add/remove
cpu by script.
>
> >>
> >> >+ cpu_hpe=on/off
> >> >+ Enable/disable cpu hotplug emulation with software method. when cpu_hpe=on,
> >> >+ sysfs provides probe/release interface to hot add/remove cpu dynamically.
> >> >+ this option is disabled in default.
> >> >+
> >>
> >> Why not just a CONFIG? IOW, why do we need to make another boot
> >> parameter for this?
> >Only the developer or QA will use the emulator, we did not want to change the
> >default action for common user who does not care the hotplug emulator, so we
> >use a kernel parameter as a switch. The common user is not aware the existence
> >of the emulator.
> >
>
> I think it is also useful to other Linux users, e.g. after I
> boot with "maxcpus=1", I can still bring the rest 3 CPU's
> back without reboot.
You understand it very well. the probe/release on ppc is already implemented,
but for x86, it is a feature missing, so we finished it with these patches.
>
> Thanks.
>
> --
> Live like a child, think like the god.
>
--
Thanks & Regards,
Shaohui
next prev parent reply other threads:[~2010-11-23 0:44 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-17 2:07 [0/8,v3] NUMA Hotplug Emulator - Introduction & Feedbacks shaohui.zheng
2010-11-17 2:08 ` [1/8,v3] NUMA Hotplug Emulator: add function to hide memory region via e820 table shaohui.zheng
2010-11-17 8:16 ` David Rientjes
2010-11-18 9:20 ` Shaohui Zheng
2010-11-18 21:16 ` David Rientjes
2010-11-19 0:12 ` Shaohui Zheng
2010-11-21 0:45 ` David Rientjes
2010-11-21 14:00 ` Américo Wang
2010-11-21 21:33 ` David Rientjes
2010-11-17 2:08 ` [2/8,v3] NUMA Hotplug Emulator: infrastructure of NUMA hotplug emulation shaohui.zheng
2010-11-17 8:16 ` David Rientjes
2010-11-17 7:51 ` Shaohui Zheng
2010-11-17 21:10 ` David Rientjes
2010-11-18 4:14 ` Shaohui Zheng
2010-11-18 6:27 ` Paul Mundt
2010-11-18 5:27 ` Shaohui Zheng
2010-11-18 21:24 ` David Rientjes
2010-11-19 0:32 ` Shaohui Zheng
2010-11-21 0:48 ` David Rientjes
2010-11-21 2:28 ` [patch 1/2] x86: add numa=possible command line option David Rientjes
2010-11-21 2:28 ` [patch 2/2] mm: add node hotplug emulation David Rientjes
2010-11-21 17:34 ` Greg KH
2010-11-21 21:48 ` David Rientjes
2010-11-21 23:08 ` [patch 2/2 v2] " David Rientjes
2010-11-22 0:56 ` Greg KH
2010-11-28 1:52 ` David Rientjes
2010-11-28 5:17 ` Greg KH
2010-11-30 0:04 ` David Rientjes
2010-11-21 14:26 ` [patch 1/2] x86: add numa=possible command line option Américo Wang
2010-11-21 21:46 ` David Rientjes
2010-11-22 15:43 ` Américo Wang
2010-11-21 15:14 ` [2/8,v3] NUMA Hotplug Emulator: infrastructure of NUMA hotplug emulation Li, Haicheng
2010-11-21 21:42 ` David Rientjes
2010-11-18 21:19 ` David Rientjes
2010-11-17 2:08 ` [3/8,v3] NUMA Hotplug Emulator: Userland interface to hotplug-add fake offlined nodes shaohui.zheng
2010-11-17 8:16 ` David Rientjes
2010-11-17 2:08 ` [4/8,v3] NUMA Hotplug Emulator: Abstract cpu register functions shaohui.zheng
2010-11-17 2:08 ` [5/8,v3] NUMA Hotplug Emulator: support cpu probe/release in x86 shaohui.zheng
2010-11-21 14:45 ` Américo Wang
2010-11-22 0:01 ` Shaohui Zheng
2010-11-22 15:51 ` Américo Wang
2010-11-22 23:29 ` Shaohui Zheng
2010-11-17 2:08 ` [6/8,v3] NUMA Hotplug Emulator: Fake CPU socket with logical CPU on x86 shaohui.zheng
2010-11-17 2:08 ` [7/8,v3] NUMA Hotplug Emulator: extend memory probe interface to support NUMA shaohui.zheng
2010-11-17 18:50 ` Dave Hansen
2010-11-17 21:18 ` David Rientjes
2010-11-17 21:55 ` Dave Hansen
2010-11-17 22:44 ` David Rientjes
2010-11-17 23:00 ` Dave Hansen
2010-11-17 23:17 ` David Rientjes
2010-11-18 16:59 ` Aaron Durbin
2010-11-18 4:48 ` Shaohui Zheng
2010-11-18 6:24 ` Paul Mundt
2010-11-18 21:28 ` David Rientjes
2010-11-18 21:31 ` David Rientjes
2010-11-18 4:36 ` Shaohui Zheng
[not found] ` <20101119075119.GD3327@shaohui>
2010-11-19 16:36 ` Dave Hansen
2010-11-17 2:08 ` [8/8,v3] NUMA Hotplug Emulator: documentation shaohui.zheng
2010-11-17 23:06 ` Randy Dunlap
2010-11-18 2:31 ` Shaohui Zheng
2010-11-21 15:03 ` Américo Wang
2010-11-21 15:16 ` Li, Haicheng
2010-11-21 23:33 ` Shaohui Zheng
2010-11-22 16:04 ` Américo Wang
2010-11-22 23:23 ` Shaohui Zheng [this message]
2010-11-17 5:22 ` [0/8,v3] NUMA Hotplug Emulator - Introduction & Feedbacks Paul Mundt
2010-11-19 5:54 ` Shaohui Zheng
2010-11-17 9:26 ` Yinghai Lu
2010-11-18 2:03 ` Shaohui Zheng
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