Re: [dpdk-dev] [PATCH 2/6] rte_log.h: add detailed log levels RTE_LOG{FINE, FINER, FINEST}

[Matthew Hall <mhall@mhcomputing.net>]

On Fri, Nov 13, 2015 at 11:48:41AM +0000, Ananyev, Konstantin wrote:
> Actually another question: are existing 8 levels not enough?
> Konstantin

Depends who you ask. I was modeling it based upon the following:

https://docs.oracle.com/javase/7/docs/api/java/util/logging/Level.html

The reason I added a previously-merged patch for a new function 
rte_get_log_level() and all these extra levels is that it allows me to do 
crazy stuff like this:

    if (rte_get_log_level() >= RTE_LOG_FINEST) {
        rte_hexdump(stderr, "header_bytes", packet->header.bytes, packet->header.header_size);
    }

It is extremely valuable to have levels which go below INFO, so you can make 
detailed trace code compiled directly into your app. Which can be readily 
enabled or disabled by setting the log_level. WAY easier to debug the early 
green-field code in your app when it crashes somehow.

Obviously the first thing you guys will say is... "BUT THAT RUNS WAY TOO 
SLOW!!!!!" and you might be right if you are processing 100 gbits/sec. But I 
am using DPDK for security not for SDN switching or core routing. And my patch 
will not introduce any performance change for the guys doing the other stuff 
either.

So if this patch is not accepted in some form, I'd be stuck with my DPDK fork 
just for this feature, and the pre-existing patches I sent to Bruce & Co. 
regarding rte_lpm and rte_lpm6 expansion and so on.

Matthew.