On 07/12/2012 05:17 AM, Benjamin Herrenschmidt wrote: >> ARM doesn't have an instruction for cpu_relax(), so it can't intercept >> it. Given ppc's dislike of overcommit, and the way it implements >> cpu_relax() by adjusting hw thread priority, I'm guessing it doesn't >> intercept those either, but I'm copying the ppc people in case I'm >> wrong. So it's s390 and x86. > > No but our spinlocks call __spin_yield() (or __rw_yield) which does > some paravirt tricks already. > > We check if the holder is currently running, and if not, we call the > H_CONFER hypercall which can be used to "give" our time slice to the > holder. > > Our implementation of H_CONFER in KVM is currently a nop though. Okay, so you can join the party. See yield_to() and kvm_vcpu_on_spin(). -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
