Re: [PATCH v3 0/4] implement vcpu preempted check
From: Peter Zijlstra
Date: Thu Sep 29 2016 - 06:32:31 EST
On Thu, Sep 29, 2016 at 12:23:19PM +0200, Christian Borntraeger wrote:
> 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)
Sure, and I had vague memories of Heiko's email. This patch set however
completely fails to do that trivial hooking up.