Messages in this thread | | | Date | Wed, 6 Jul 2016 13:59:54 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 0/4] implement vcpu preempted check |
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On Wed, Jul 06, 2016 at 12:44:58PM +0200, Paolo Bonzini wrote: > > Paolo, could you help out with an (x86) KVM interface for this? > > If it's just for spin loops, you can check if the version field in the > steal time structure has changed.
That would require remembering the old value, no?
That would work with a previous interface proposal, see:
http://lkml.kernel.org/r/1466937715-6683-2-git-send-email-xinhui.pan@linux.vnet.ibm.com
the vcpu_get_yield_count() thing would match that I think.
However the current proposal:
http://lkml.kernel.org/r/1467124991-13164-2-git-send-email-xinhui.pan@linux.vnet.ibm.com
dropped that in favour of only vcpu_is_preempted(), which requires being able to tell if a (remote) vcpu is currently running or not, which iirc, isn't possible with the steal time sequence count.
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