Hi Gokul,
As Setphen said, only Mellanox sets the hardware timestamp.
If you have a Mellanox card, you can actually follow the example given
in the rxtx_callback sample application that precisely gives the number
of CPU cycles a packet spent into the queue.
Tom
Le 22/11/2019 à 18:00, Gokul Bargaje a écrit :
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.yi...@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*?
