On 18-10-19 16:20:52, Juergen Gross wrote: > On 19/10/2018 15:13, Yi Sun wrote:
[...] > > diff --git a/kernel/locking/qspinlock_paravirt.h > > b/kernel/locking/qspinlock_paravirt.h > > index 0130e48..9e88c7e 100644 > > --- a/kernel/locking/qspinlock_paravirt.h > > +++ b/kernel/locking/qspinlock_paravirt.h > > @@ -7,6 +7,8 @@ > > #include <linux/bootmem.h> > > #include <linux/debug_locks.h> > > > > +#include <asm/mshyperv.h> > > + > > /* > > * Implement paravirt qspinlocks; the general idea is to halt the vcpus > > instead > > * of spinning them. > > @@ -305,6 +307,10 @@ static void pv_wait_node(struct mcs_spinlock *node, > > struct mcs_spinlock *prev) > > wait_early = true; > > break; > > } > > +#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS) && > > IS_ENABLED(CONFIG_HYPERV) > > + if (!hv_notify_long_spin_wait(SPIN_THRESHOLD - loop)) > > + break; > > +#endif > > I don't like that. Why should a KVM or Xen guest call into a hyperv > specific function? > > Can't you move this to existing hyperv specific paravirt hooks? > hv_notify_long_spin_wait() must be called in this loop but it seems there is no appropriate existing paravirt hook here. So, can I add one more hook in pv_lock_ops to do this notification? > > Juergen
