[dpdk-dev] cost of reading tsc register

[Matthew Hall]

On Mon, Apr 20, 2015 at 02:37:53PM +0000, Ravi Kumar Iyer wrote:
> We were doing some code optimizations , running DPDK based applications, and chanced upon the rte_rdtsc function [ to read tsc timestamp register value ] consuming cpu cycles of the order of 100clock cycles with a delta of upto 40cycles at times [ 60-140 cycles]
> 
> We are actually building up a cpu intensive application which is also very clock cycle sensitive and this is impacting our implementation.
> 
> To validate the same using a small/vanilla application we wrote a small code and tested on a single core.
> Has anyone else faced a similar issue or are we doing something really atrocious here.

What happened when you tried rte_rdtsc_precise ?

Matthew.