Messages in this thread | | | Subject | Re: [PATCH RFC 0/2] kvm: Improving directed yield in PLE handler | From | Benjamin Herrenschmidt <> | Date | Thu, 12 Jul 2012 12:17:39 +1000 |
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> ARM doesn't have an instruction for cpu_relax(), so it can't intercept > it. Given ppc's dislike of overcommit, and the way it implements > cpu_relax() by adjusting hw thread priority, I'm guessing it doesn't > intercept those either, but I'm copying the ppc people in case I'm > wrong. So it's s390 and x86.
No but our spinlocks call __spin_yield() (or __rw_yield) which does some paravirt tricks already.
We check if the holder is currently running, and if not, we call the H_CONFER hypercall which can be used to "give" our time slice to the holder.
Our implementation of H_CONFER in KVM is currently a nop though.
Cheers, Ben.
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