On 2016年06月27日 22:02, Peter Zijlstra wrote:

On Mon, Jun 27, 2016 at 04:00:43PM +0200, Peter Zijlstra wrote:

quoted

On Mon, Jun 27, 2016 at 01:41:28PM -0400, Pan Xinhui wrote:

quoted

+++ b/include/linux/sched.h

@@ -3293,6 +3293,15 @@ static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)

  #endif /* CONFIG_SMP */

+#ifdef arch_vcpu_is_preempted
+static inline bool vcpu_is_preempted(int cpu)
+{
+	return arch_vcpu_is_preempted(cpu);
+}
+#else
+#define vcpu_is_preempted(cpu)	false
+#endif

#ifndef vcpu_is_preempted
#define vcpu_is_preempted(cpu)		(false)
#endif

Is so much simpler...

fair enough.

quoted

Also, please Cc the virt list so that other interested parties can
comment, and maybe also the s390 folks.

oh. I forgot that. maybe we need cc more.

root@ltcalpine2-lp13:~/linux# find ./arch -name kvm
./arch/arm/kvm
./arch/arm64/kvm
./arch/mips/kvm
./arch/powerpc/kvm
./arch/s390/kvm
./arch/tile/kvm
./arch/x86/kvm

And before you hurry off to post again, add a patch doing
mutex_spin_on_owner() and rwsem_spin_in_owner().

will do that.

thanks for your suggestion. :)