On 18-10-23 17:33:28, Yi Sun wrote: > On 18-10-23 10:51:27, Peter Zijlstra wrote: > > On Tue, Oct 23, 2018 at 10:57:40AM +0800, Yi Sun wrote: > > > On 18-10-22 19:15:16, Peter Zijlstra wrote: > > > > > > > >>>> +#if defined(CONFIG_X86_64) && > > > > > >>>> defined(CONFIG_PARAVIRT_SPINLOCKS) && IS_ENABLED(CONFIG_HYPERV) > > > > > >>>> + if > > > > > >>>> (!hv_notify_long_spin_wait(SPIN_THRESHOLD - loop)) > > > > > >>>> + break; > > > > > >>>> +#endif > > > > > > > > Secondly; how come you thought that was acceptable in any way shape or > > > > form? > > > > > > > Sorry for that. Will try another way. > > > > Can you try and explain why vcpu_is_preempted() doesn't work for you? > > I thought HvSpinWaitInfo is used to notify hypervisor the spin number > which is different with vcpu_is_preempted. So I did not consider > vcpu_is_preempted. > > But HvSpinWaitInfo is a quite simple function and could be combined > with vcpu_is_preempted together. So I think it is OK to use > vcpu_is_preempted to make codes clean. I will have a try.
After checking codes, there is one issue to call vcpu_is_preempted. There are two spin loops in qspinlock_paravirt.h. One loop in 'pv_wait_node' calls vcpu_is_preempted. But another loop in 'pv_wait_head_or_lock' does not call vcpu_is_preempted. It also does not call any other ops of 'pv_lock_ops' in the loop. So I am afraid we have to add one more ops in 'pv_lock_ops' to do this.