On Thu, Sep 29, 2016 at 12:23:19PM +0200, Christian Borntraeger wrote:

On 09/29/2016 12:10 PM, Peter Zijlstra wrote:

quoted

On Thu, Jul 21, 2016 at 07:45:10AM -0400, Pan Xinhui wrote:

quoted

change from v2:
	no code change, fix typos, update some comments

change from v1:
	a simplier definition of default vcpu_is_preempted
	skip mahcine type check on ppc, and add config. remove dedicated macro.
	add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. 
	add more comments
	thanks boqun and Peter's suggestion.

This patch set aims to fix lock holder preemption issues.

So I really like the concept, but I would also really like to see
support for more hypervisors included before we can move forward with
this.

Please consider s390 and (x86/arm) KVM. Once we have a few, more can
follow later, but I think its important to not only have PPC support for
this.

Actually the s390 preemted check via sigp sense running  is available for
all hypervisors (z/VM, LPAR and KVM) which implies everywhere as you can no
longer buy s390 systems without LPAR.

As Heiko already pointed out we could simply use a small inline function
that calls cpu_is_preempted from arch/s390/lib/spinlock (or smp_vcpu_scheduled from smp.c)

Sure, and I had vague memories of Heiko's email. This patch set however
completely fails to do that trivial hooking up.