[dpdk-dev] [PATCH v7 02/10] eal: add power management intrinsics

[Ruifeng Wang]

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
> Sent: Tuesday, October 20, 2020 5:13 AM
> To: Ruifeng Wang <Ruifeng.Wang at arm.com>; Honnappa Nagarahalli
> <Honnappa.Nagarahalli at arm.com>
> Cc: dev at dpdk.org; Liang Ma <liang.j.ma at intel.com>; Jan Viktorin
> <viktorin at rehivetech.com>; David Christensen <drc at linux.vnet.ibm.com>;
> Bruce Richardson <bruce.richardson at intel.com>; Konstantin Ananyev
> <konstantin.ananyev at intel.com>; david.hunt at intel.com;
> jerinjacobk at gmail.com; timothy.mcdaniel at intel.com; gage.eads at intel.com;
> chris.macnamara at intel.com; Anatoly Burakov <anatoly.burakov at intel.com>;
> david.marchand at redhat.com
> Subject: Re: [dpdk-dev] [PATCH v7 02/10] eal: add power management
> intrinsics
> 
> 15/10/2020 14:04, Anatoly Burakov:
> > +/**
> > + * This function is not supported on ARM.
> > + */
> > +static inline void
> > +rte_power_monitor(const volatile void *p, const uint64_t
> expected_value,
> > +               const uint64_t value_mask, const uint64_t tsc_timestamp,
> > +               const uint8_t data_sz) {
> > +       RTE_SET_USED(p);
> > +       RTE_SET_USED(expected_value);
> > +       RTE_SET_USED(value_mask);
> > +       RTE_SET_USED(tsc_timestamp);
> > +       RTE_SET_USED(data_sz);
> > +}
> 
> Are you sure it cannot be partially supported with WFE instruction?
> 
Armv8 WFE instruction can support monitoring of specific address for changes, 
but not monitoring of TSC timestamp.