Hi all, There is a macro current which may mean to get the current vcpu information. But the physical machine may be multi-core ,thus there may be two or more vcpus running in parallel on different cores.Then which vcpu is the current? How should I understand the current vcpu please? Thanks. Cheer, -- zp _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jeremy Fitzhardinge
2009-Mar-28 05:16 UTC
Re: [Xen-devel] Question about the current vcpu.
p z wrote:> But the physical machine may be multi-core ,thus there may be two or > more vcpus running in parallel on different cores.Then which vcpu is > the current? How should I understand the current vcpu please?"current" returns the vcpu currently running on this physical cpu (ie, the one that''s executing "current" itself). It will return different results for each pcpu at a given instant, and will return different values for a given pcpu over time as different vcpus are scheduled on itnb. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Hi, Actually, defined by Credit scheduler, each PCPU (physical CPU, if you run Xen on a multi-core machine, you get multiple PCPUs) has its own runqueue, and its own current vcpu as well. The PCPUs of the system makes their own scheduling decisions independently. Best, 2009-03-30 Zhiyuan Shao 发件人： p z 发送时间： 2009-03-28 09:38:16 收件人： xen-devel@lists.xensource.com 抄送： 主题： [Xen-devel] Question about the current vcpu. Hi all, There is a macro current which may mean to get the current vcpu information. But the physical machine may be multi-core ,thus there may be two or more vcpus running in parallel on different cores.Then which vcpu is the current? How should I understand the current vcpu please? Thanks. Cheer, -- zp _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel