From: Tang Chen <tangchen@cn.fujitsu.com>
To: Borislav Petkov <bp@alien8.de>,
"Luck, Tony" <tony.luck@intel.com>,
Borislav Petkov <bp@amd64.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"hpa@zytor.com" <hpa@zytor.com>,
"miaox@cn.fujitsu.com" <miaox@cn.fujitsu.com>,
"laijs@cn.fujitsu.com" <laijs@cn.fujitsu.com>,
"wency@cn.fujitsu.com" <wency@cn.fujitsu.com>,
"x86@kernel.org" <x86@kernel.org>,
"linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/2] Do not change worker's running cpu in cmci_rediscover().
Date: Tue, 23 Oct 2012 09:30:35 +0800 [thread overview]
Message-ID: <5085F33B.501@cn.fujitsu.com> (raw)
In-Reply-To: <20121022101804.GC8352@liondog.tnic>
On 10/22/2012 06:18 PM, Borislav Petkov wrote:
> On Mon, Oct 22, 2012 at 11:33:16AM +0800, Tang Chen wrote:
>> I have 2 nodes, node0 and node1. node1 could be hotpluged.
>> node0 has cpu0 ~ cpu15, node1 has cpu16 ~ cpu31.
>>
>> I online all the cpus on node1, and hot-remove node1 directly.
>
> Hold on, I need to ask here: you soft-online all cores on node1 and
> *then* you *hot* *remove* it? So with all cores online you physically
> take out the processor from the socket? Am I reading this correctly?
Hi Borislav,
No, it's not like that. I'm sorry to make you confused.
Firstly, let me do a little explanation here. :)
I was doing ACPI based hotplug. In a container device, it contains
cpus and memories and so on. I didn't physically remove cpus from
hardware. I emulated a SCI with my own test module, and the
container_notify_cb() was called, and it recursively remove all the
sub-devices.
The "remove" here doesn't mean "taking it away". And of course, when
the "remove" is done, you can physically take the whole system board
away.
Please refer to this url:
http://www.spinics.net/lists/linux-pci/msg17651.html
This is the module we are doing the SCI emulation.
In summary, the hotplug process could be like the following:
hot-add(SCI) -> online(softly) -> device working -> offline(softly) ->
hot-remove(SCI)
Secondly, in kernel, before a container device is removed, all its
sub-devices will be offlined and removed first. So I have all the cpus
online, and hot-remove a container(which I think is a node, maybe not)
directly. This operation has no problem, I think.
Maybe I should not say container as a node. :)
And again, sorry for the confusion.
Thanks. :)
>
> Thanks.
>
next prev parent reply other threads:[~2012-10-23 1:31 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-19 5:45 [PATCH v2 0/2] Do not change worker's running cpu in cmci_rediscover() Tang Chen
2012-10-19 5:45 ` [PATCH v2 1/2] Replace if statement with WARN_ON_ONCE() " Tang Chen
2012-10-19 14:07 ` Greg KH
2012-10-19 16:40 ` Borislav Petkov
2012-10-22 2:10 ` Tang Chen
2012-10-22 10:14 ` Borislav Petkov
2012-10-23 1:35 ` Tang Chen
2012-10-23 2:55 ` Tang Chen
2012-10-23 9:52 ` Borislav Petkov
2012-10-23 10:17 ` Miao Xie
2012-10-23 10:20 ` Borislav Petkov
2012-10-23 10:34 ` Miao Xie
2012-10-23 13:14 ` Borislav Petkov
2012-10-23 11:30 ` Tang Chen
2012-10-23 14:17 ` Borislav Petkov
2012-10-23 16:16 ` Luck, Tony
2012-10-24 1:31 ` Tang Chen
2012-10-19 5:45 ` [PATCH v2 2/2] Do not change worker's running cpu " Tang Chen
2012-10-19 16:42 ` Borislav Petkov
2012-10-19 17:21 ` Luck, Tony
2012-10-22 3:33 ` Tang Chen
2012-10-22 10:18 ` Borislav Petkov
2012-10-23 1:30 ` Tang Chen [this message]
2012-10-19 7:21 ` [PATCH v2 0/2] " Tang Chen
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