From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to
 support pv-ticketlock
Date: Thu, 20 Jan 2011 14:41:46 +0100
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Cc: Mathieu, Xen-devel <xen-devel@lists.xensource.com>,
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On Thu, 2011-01-20 at 17:29 +0530, Srivatsa Vaddagiri wrote:
>=20
> If we had a yield-to [1] sort of interface _and_ information on which vcp=
u
> owns a lock, then lock-spinners can yield-to the owning vcpu,=20

and then I'd nak it for being stupid ;-)

really, yield*() is retarded, never even consider using it. If you've
got the actual owner you can do full blown PI, which is tons better than
a 'do-something-random' call.

The only reason the whole non-virt pause loop filtering muck uses it is
because it really doesn't know anything, and do-something is pretty much
all it can do. Its a broken interface.