Re: [dpdk-dev] [dpdk-users] What is the 'unit of timestamp' assigned to mbuf packet in DPDK?

[Gokul Bargaje <gokulbargaje.182009@nitk.edu.in>]

Thank you for the clarification. But I am still unable to understand how
exactly timestamp is calculated before assigning to a timestamp field.
Could you please tell me the steps to calculate the timestamp in DPDK?

I have to implement the PIE AQM algorithm in DPDK and for that, I need to
calculate the total time spent by the packet waiting in queue (i.e. the
difference between enqueue time and dequeue time).

Thanks,
Gokul

On Fri, Nov 22, 2019 at 8:18 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:

> On 11/18/2019 2:29 PM, Gokul Bargaje wrote:
> > Hi,
> >
> > The timestamp assigned to packet at the time of enqueue (value of
> timestamp
> > field in mbuf), is it in milliseconds or microseconds or in cpu cycles?
>
> The unit is not defined [1]. 'rte_eth_read_clock()' was added [2] to help
> converting it to time when it is clock counter.
>
> [1]
> 918ae9dc775e ("mbuf: add a timestamp field")
>
> [2]
> 5e741377657c ("ethdev: add API to read device clock")
>
> >
> > How this timestamp is calculated? Is it calculated using the
> *rte_cycles.h*?
> >
>
>
>
>
>
>