From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
gregkh@linuxfoundation.org
Subject: Re: [Xen-devel] [PATCH] xen/cpu: Make VCPU hotplug code online CPUs properly.
Date: Fri, 10 Feb 2012 10:42:55 -0500 [thread overview]
Message-ID: <20120210154255.GA9857@phenom.dumpdata.com> (raw)
In-Reply-To: <1328886226.6133.271.camel@zakaz.uk.xensource.com>
On Fri, Feb 10, 2012 at 03:03:46PM +0000, Ian Campbell wrote:
> On Fri, 2012-02-10 at 14:43 +0000, Konrad Rzeszutek Wilk wrote:
> > Offlining CPUs works. Onlining does not work anymore and it looks
> > like we were missing a cpu_up() call in the hotplug bring up path.
>
> Wasn't this a deliberate decision as part of the pvops upstreaming to be
> consistent with native cpu hotplug? After hotplugging a CPU
Ah, hadn't seen that. Thanks for spotting that!
> administrator action is needed to actually online it.
>
> http://xen.1045712.n5.nabble.com/cpu-down-but-no-cpu-up-in-drivers-xen-cpu-hotplug-c-td2545244.html
>
> The fix is to add a udev rule:
> http://wiki.xen.org/wiki/Paravirt_Linux_CPU_Hotplug
Ah, so I see that it is run (the udev does it) but it actually does not bring the CPU up.
It looks as if the 'online' attribute is actually not present at all, even
after bringing the CPU "up-but-not-online". Oh joy! Should be easy to reproduce
on baremetal.
prev parent reply other threads:[~2012-02-10 15:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-10 14:43 [PATCH] vcpu hotplug fix for v3.3-rc3 (v1) Konrad Rzeszutek Wilk
2012-02-10 14:43 ` [PATCH] xen/cpu: Make VCPU hotplug code online CPUs properly Konrad Rzeszutek Wilk
2012-02-10 15:03 ` [Xen-devel] " Ian Campbell
2012-02-10 15:42 ` Konrad Rzeszutek Wilk [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120210154255.GA9857@phenom.dumpdata.com \
--to=konrad.wilk@oracle.com \
--cc=Ian.Campbell@citrix.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=xen-devel@lists.xensource.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).