[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] Question about the ability of credit scheduler to handle I/O and CPU intensive VMs
The file you're looking for re getting an event channel is xen/common/schedule.c, the common scheduling code. In schedule.c, vcpu_wake() will always call the scheduler wake() function; However, event channels and other "you have an event" functions call call vcpu_unblock() instead, which will check the vcpu's VPF_blocked flag and only call vcpu_wake if it was set. You could try changing vcpu_unblock() to always call vcpu_wake() for your experimental development; I'm not sure what side-effects this would have. Regarding tracing IO_READs: The code that did IO was refactored some time back; I remember trying to figure out how to cleanly do the tracing, but finding it difficult. I can't remember now, though, what the issue was. Let me take a look again. -George On Fri, Oct 8, 2010 at 1:25 AM, Yuehai Xu <yuehaixu@xxxxxxxxx> wrote: >> I originally considered that when a Dom has an I/O event, its VCPU >> would be waken up, in another word, csched_vcpu_wake(struct vcpu *vc) >> should be invoked. However, I find I am definitely wrong. As long as >> there is a CPU intensive program running in a Dom, this Dom should >> never be in a state of "sleep"? In another word, it should never be >> waken up? >> > > The trace result from xenalyze confirms that when a VM has a running > CPU intensive program, it never needs to be waken up. So, my question > is, how can I schedule a VM that has I/O event immediately even this > VM is CPU intensive? I think it is impossible to implement it in the > function csched_vcpu_wake. > > Also, is it possible to trace the I/O procedure by xenalyze? I notice > even the macro TRC_HVM_IO_READ is defined, I don't find it is used in > anywhere. > > Thanks, > Yuehai > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |