On Tue, May 12, 2015 at 8:16 PM, Ravi Kerur <rkerur at gmail.com> wrote:
> On Mon, May 11, 2015 at 3:29 PM, Don Provan <dprovan at bivio.net> wrote: > > > I probably shouldn't stick my nose into this, but I can't help myself. > > > > An experienced programmer will tend to ignore the documentation for > > a routine named "blahblah_memcmp" and just assume it functions like > > memcmp. Whether or not there's currently a use case in DPDK is > > completely irrelevant because as soon as there *is* a use case, some > > poor DPDK developer will try to use rte_memcmp for that and may or > > may not have a test case that reveals their mistake. > > > > In general I agree with you. However, comparison is a hit(equal) or > miss(unequal) is generally the case in networking. I haven't seen cases > where "less than" or "greater than" has mattered. > It's useful when you need to make sure packets from both sides of a conversation go to the same processing queue/thread. Instead of hashing the 5-tuple from the packet as src.ip, dst.ip, src.dport, dst.dport, etc., you can use lesser.ip, higher.ip, lesser.sport, higher.dport, etc. Very common when you are doing deep packet inspection. Jay
