[lkml]   [2009]   [Oct]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH v2 2/4] KVM: introduce "xinterface" API for external interaction with guests
    On 10/07/2009 02:48 PM, Gregory Haskins wrote:
    >> If f() can cause another agent to write to p (by freeing
    >> it to a global list, for example), then it is its responsibility to
    >> issue the smp_rmb(), otherwise no calculation that took place before f()
    >> and accessed p is safe.
    > IOW: David is right. You need a cpu-barrier one way or the other. We
    > can either allow ->release() to imply one (and probably document it that
    > way, like we did for slow-work), or we can be explicit.

    No, ->release() must do it or it becomes impossible to program. And in
    fact it will, to place the freed structure on a global list it must take
    a lock which implies an smp_rmb().

    > I chose to be
    > explicit since it is kind of self-documenting, and there is no need to
    > be worried about performance since the release is slow-path.

    It's so self-documenting I had no idea what it was there for.

    error compiling committee.c: too many arguments to function

     \ /
      Last update: 2009-10-08 16:55    [W:0.028 / U:1.452 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site