rte_rdtsc() - what is the performance impact of using rte_rdtsc() time

[Hari Haran]

Hi All,

Subject: rte_rdtsc() - what is the performance impact of using rte_rdtsc()
time under lcore thread while(1)

Requirement:

   1. Store the packet received timestamp - based on it packets will be
   removed from buffer if it exceeds the threshold timer of buffer
   2. Two threads are available, One is lcore(dedicated core) and another
   is pthread(not a dedicated core. In pthread, have to get the timestamp of
   last received packet timestamp


Query:

   1. For every packet reception in lcore thread under while(1), will get
   the packet received timestamp using  rte_rdtsc() function. Whether usage of
   rte_rdtsc() function adds more delay in packet processing?
   2. Is there any way to convert rte_rdtsc() timestamp value to current
   system time in pthread()? In pthread, the last packet received time needed
   in the form of system time.


Thanks in advance.

Regards,
Hariharan