[lkml]   [2012]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH RFC 0/2] kvm: Improving directed yield in PLE handler
    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

     \ /
      Last update: 2012-07-10 01:01    [W:0.029 / U:0.852 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site