> (One example might be virtual machine that runs guest operating system that is > not paravirtualized or can be paravirtualized only to a limited extent. The VM > might guess that preemption of VCPU thread that is processing events such as > IPI interrupts, clock interrupts or certain device interrupts is likely to > cause overall performance degradation due to other VCPUs spinning for an IPI > response or spinning waiting for a spinlock, and thought the general kinds of > these dependencies may be foreseen, but actual dependency chains between VCPUs > cannot be established at run time.)
PAUSE loop exiting (PLE) can handle it in limited fashion on VMs even without paravirtualization. -Andi -- [email protected] -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
