Re: [PATCH v3 0/4] implement vcpu preempted check

[Christian Borntraeger]

On 09/29/2016 12:10 PM, Peter Zijlstra wrote:
> On Thu, Jul 21, 2016 at 07:45:10AM -0400, Pan Xinhui wrote:
>> 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)

Christian