* Srivatsa Vaddagiri <vatsa@xxxxxxxxxxxxxxxxxx> [2012-03-31 09:37:45]: > The issue is with ticketlocks though. VCPUs could go into a spin w/o > a lock being held by anybody. Say VCPUs 1-99 try to grab a lock in > that order (on a host with one cpu). VCPU1 wins (after VCPU0 releases it) > and releases the lock. VCPU1 is next eligible to take the lock. If Sorry I meant to say "VCPU2 is next eligible ..." > that is not scheduled early enough by host, then remaining vcpus would keep > spinning (even though lock is technically not held by anybody) w/o making > forward progress. > > In that situation, what we really need is for the guest to hint to host > scheduler to schedule VCPU1 early (via yield_to or something similar). s/VCPU1/VCPU2 .. - vatsa -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
