Re: [dpdk-dev] [RFC v2] ethdev: add IF-MIB attributes implementation

[Thomas Monjalon <thomas@monjalon.net>]

14/07/2017 02:07, Stephen Hemminger:
> On Thu, 13 Jul 2017 17:24:27 +0100
> Reshma Pattan <reshma.pattan@intel.com> wrote:
> 
> > diff --git a/lib/librte_ether/rte_ethdev_pci.h b/lib/librte_ether/rte_ethdev_pci.h
> > index 69aab03..f829407 100644
> > --- a/lib/librte_ether/rte_ethdev_pci.h
> > +++ b/lib/librte_ether/rte_ethdev_pci.h
> > @@ -37,6 +37,7 @@
> >  #include <rte_malloc.h>
> >  #include <rte_pci.h>
> >  #include <rte_ethdev.h>
> > +#include <rte_cycles.h>
> >  
> >  /**
> >   * Copy pci device info to the Ethernet device data.
> > @@ -157,6 +158,9 @@ rte_eth_dev_pci_generic_probe(struct rte_pci_device *pci_dev,
> >  
> >  	RTE_FUNC_PTR_OR_ERR_RET(*dev_init, -EINVAL);
> >  	ret = dev_init(eth_dev);
> > +	eth_dev->data->sys_up_time_start = rte_rdtsc();
> > +	eth_dev->data->if_counter_discontinuity_time = 0;
> > +	eth_dev->data->if_last_change = 0;
> 
> Shouldn't this be in base eth_dev layer rather than the  PCI specific code.
> 
> If you look in rte_eth_dev_data_alloc, the dev_data is already zeroed.
> 
> Also, DPDK in general does BSD style structure names (ie always putting prefix
> on structure tags). In BSD, this is a leftover from ancient V6 UNIX where
> compiler did no real checking of structure tags. My preference is that
> variables and structure names be as short as possible.
> 
> The TSC counter is not a good value to use on this anyway. You don't care
> about sub-microsecond accuracy and it wraps around. Better to figure out
> a better clock source. Is there a DPDK wrapper of clock_gettime(CLOCK_MONOTONIC)?

In rte_cycles.h, the TSC is wrapped into rte_get_timer_cycles().
About clock_gettime(CLOCK_MONOTONIC), I think we may need to create
a file rte_clock.h.