From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Zhigang Wang <zhigang.x.wang@oracle.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Ian Jackson <Ian.Jackson@eu.citrix.com>
Subject: Re: xl: expose max_cpu_id from `xl info`
Date: Wed, 14 Mar 2012 16:24:25 +0000 [thread overview]
Message-ID: <4F60C639.1020307@citrix.com> (raw)
In-Reply-To: <4F60BDBA.3040209@oracle.com>
<snip>
>>> Is this true: nr_cpus = max_cpu_id + 1 ?
>>>
>>> Zhigang
>>
>> if and only if all cpus are online.
>>
>> nr_cpus is set to nr_online_cpus() in the hypercall, while max_cpu_id
>> is set to nr_cpu_ids-1.
>>
>> nr_cpus is liable to change during runtime, while max_cpu_id is not.
>>
>> ~Andrew
>
> If this is the case, I think nr_cpus is a bit confusing. Can we make
> it always representing the number of physical cpus (from hypervisor's
> viewpoint, not dom0)?
>
> Zhigang
>
>
No. The names here reflect the hypercall name parameters. The
hypercall cant be changed because it is an ABI, and the "name : value"
pairs here cant be changed because of backward compatibility with the
previous toolstack.
--
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com
next prev parent reply other threads:[~2012-03-14 16:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 16:52 xl: expose max_cpu_id from `xl info` Andrew Cooper
2012-03-13 19:15 ` Zhigang Wang
2012-03-14 10:45 ` Andrew Cooper
2012-03-14 15:48 ` Zhigang Wang
2012-03-14 16:24 ` Andrew Cooper [this message]
2012-03-14 17:51 ` Zhigang Wang
2012-03-14 11:10 ` Ian Jackson
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