Messages in this thread | | | Date | Mon, 22 Oct 2018 09:53:42 +0800 | From | Yi Sun <> | Subject | Re: [PATCH v1 2/2] x86/hyperv: make HvNotifyLongSpinWait hypercall |
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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
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