On 07/09/2012 02:20 AM, Raghavendra K T wrote:
Currently Pause Looop Exit (PLE) handler is doing directed yield to a random VCPU on PL exit. Though we already have filtering while choosing the candidate to yield_to, we can do better. Problem is, for large vcpu guests, we have more probability of yielding to a bad vcpu. We are not able to prevent directed yield to same guy who has done PL exit recently, who perhaps spins again and wastes CPU. Fix that by keeping track of who has done PL exit. So The Algorithm in series give chance to a VCPU which has: (a) Not done PLE exit at all (probably he is preempted lock-holder) (b) VCPU skipped in last iteration because it did PL exit, and probably has become eligible now (next eligible lock holder) Future enhancemnets:
Your patch series looks good to me. Simple changes with a significant result. However, the simple heuristic could use some comments :) -- All rights reversed -- 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
