From: Keir Fraser <keir.fraser@eu.citrix.com>
To: Dan Magenheimer <dan.magenheimer@oracle.com>,
"Xen-Devel (xen-devel@lists.xensource.com)"
<xen-devel@lists.xensource.com>
Subject: Re: [RFC] Physical hot-add cpus and TSC
Date: Wed, 26 May 2010 16:45:49 +0100 [thread overview]
Message-ID: <C82300BD.15EF3%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <3c6e0679-a0b8-42ae-9e86-36e7fa260e73@default>
On 26/05/2010 16:19, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:
> Much of the TSC-based time infrastructure in Xen,
> especially as exposed to guests, is rather sensitive
> to sudden dramatic differences in TSC values between
> physical processors. Hot-add of physical CPUs will
> introduce a huge difference.
True at the moment, but can we not just whack the TSC of the newly added CPU
on the head when it is brought online, to match the boot CPU? I think that
would suffice for systems with 'reliable tsc' which are the only ones we
don't emulate tsc by default?
-- Keir
next prev parent reply other threads:[~2010-05-26 15:45 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-26 15:19 [RFC] Physical hot-add cpus and TSC Dan Magenheimer
2010-05-26 15:45 ` Keir Fraser [this message]
2010-05-26 16:44 ` Dan Magenheimer
2010-05-26 17:02 ` Ian Pratt
2010-05-26 17:29 ` Keir Fraser
2010-05-26 17:39 ` Dan Magenheimer
2010-05-26 17:51 ` Keir Fraser
2010-05-26 18:01 ` Keir Fraser
2010-05-26 19:46 ` Dan Magenheimer
2010-05-26 21:26 ` Keir Fraser
2010-05-27 6:15 ` Jiang, Yunhong
2010-05-27 6:57 ` Keir Fraser
2010-05-27 7:09 ` Jiang, Yunhong
2010-05-27 7:15 ` Jiang, Yunhong
2010-05-27 19:55 ` Dan Magenheimer
2010-05-27 8:44 ` Keir Fraser
2010-05-27 9:31 ` Jiang, Yunhong
2010-05-27 15:08 ` Dan Magenheimer
2010-05-28 5:39 ` Jiang, Yunhong
2010-05-28 5:47 ` Keir Fraser
2010-05-28 6:29 ` Jiang, Yunhong
2010-05-28 7:03 ` Keir Fraser
2010-05-28 14:35 ` Dan Magenheimer
2010-05-28 15:33 ` Jiang, Yunhong
2010-05-28 16:25 ` Dan Magenheimer
2010-05-31 8:56 ` Jiang, Yunhong
2010-05-28 16:08 ` Keir Fraser
2010-05-28 16:36 ` Dan Magenheimer
2010-05-28 17:19 ` Keir Fraser
2010-05-28 14:52 ` Dan Magenheimer
2010-05-28 15:05 ` Jiang, Yunhong
2010-05-28 20:24 ` Dan Magenheimer
2010-05-31 7:54 ` Jiang, Yunhong
2010-06-01 0:30 ` Dan Magenheimer
2010-06-01 1:40 ` Jiang, Yunhong
2010-06-01 17:07 ` Jeremy Fitzhardinge
2010-06-02 9:17 ` Jiang, Yunhong
2010-06-10 6:55 ` Dong, Eddie
2010-06-10 13:15 ` Dan Magenheimer
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