>>> "Zhang, Yang Z" <yang.z.zh...@intel.com> 09/18/15 2:29 AM >>> >Zhang, Yang Z wrote on 2015-09-08: >I have a quick check on current code. I am curious that is current Xen > preemptive?
> Also, when return from an interrupt handler, hypervisor didn't check > whether reschedule is needed if the interrupt is occurred in kernel context. >ENTRY(ret_from_intr) >GET_CURRENT(%rbx) >testb $3,UREGS_cs(%rsp) >jz restore_all_xen //call iret directly to restore previous context where interrupt occur if it is in kernel space. >If Xen isn't preemptive, the above case I mentioned should never happen since > the VCPU still run in the same PCPU. Am I right? I have to admit that I don't see the connection to preemptiveness: The reference above is to a code section with interrupts disabled. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel