From: Keir Fraser <keir.fraser@eu.citrix.com>
To: Jan Beulich <JBeulich@novell.com>,
Yunhong Jiang <yunhong.jiang@intel.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: RE: [PATCH] Allocate vmcs pages when system booting
Date: Fri, 15 Jan 2010 10:31:39 +0000 [thread overview]
Message-ID: <C775F48B.66D1%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <4B5043B8020000780002A2E9@vpn.id2.novell.com>
On 15/01/2010 09:30, "Jan Beulich" <JBeulich@novell.com> wrote:
>>>> "Jiang, Yunhong" <yunhong.jiang@intel.com> 15.01.10 10:06 >>>
>> b) Can we still turn to the original patch, i.e. pre-allocate all VMCS pages
>> for all possible CPU?
>
> I'm generally opposed to pre-allocations, at least as long as all CPUs are
> considered 'possible'. Building with a relatively high nr_cpus= setting
> and then running on a relatively small system results in (close to)
> unacceptable overhead.
>
> In fact it's really not clear to me why cpu_possible_map must be set to
> CPU_MASK_ALL - if Linux has ways to avoid this, Xen should have too.
Does Linux manage a good reliable job of cutting down cpu_possible_map? That
would save cpu_possible_map in my eyes, if we could do that. Otherwise it is
indeed pretty useless now. Either way, I'd like cpu hotplug notifier chains
in the 4.1 development window.
-- Keir
next prev parent reply other threads:[~2010-01-15 10:31 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-12 10:52 [PATCH] Allocate vmcs pages when system booting Jiang, Yunhong
2009-11-12 11:22 ` Keir Fraser
2009-11-12 14:58 ` Jiang, Yunhong
2009-11-12 15:04 ` Keir Fraser
2009-11-12 15:15 ` Jiang, Yunhong
2010-01-15 9:06 ` Jiang, Yunhong
2010-01-15 9:30 ` Jan Beulich
2010-01-15 10:31 ` Keir Fraser [this message]
2010-01-17 2:02 ` Jiang, Yunhong
2010-01-17 21:35 ` Keir Fraser
2010-01-18 8:11 ` Keir Fraser
2010-01-18 8:22 ` Jiang, Yunhong
2010-03-18 10:45 ` Jan Beulich
2010-03-18 10:51 ` Keir Fraser
2010-03-19 2:17 ` Jiang, Yunhong
2010-01-15 10:28 ` Keir Fraser
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