[dpdk-dev] [RFC] DPDK Trace support

[Stephen Hemminger]

On Sat, 18 Jan 2020 10:14:31 -0500
<dave at barachs.net> wrote:

> It would be well worth considering one of the vpp techniques to minimize trace impact:
> 
> static inline ring_handler_inline (..., int is_traced)
> {
>   for (i = 0; i < vector_size; i++)
>     {
>       if (is_traced)
> 	{
> 	  do_trace_work;
> 	}
>       normal_packet_processing;
>     }
> }
> 
> ring_handler (...)
> {
>   if (PREDICT_FALSE(global_trace_flag != 0))
>     return ring_handler_inline (..., 1 /* is_traced */);
>   else
>     return ring_handler_inline (..., 0 /* is_traced */);
> }
> 
> This reduces the runtime tax to the absolute minimum, but costs space. 
> 
> Please consider it.
> 
> HTH... Dave

LTTng already has tracepoint_enabled for this