> -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com] > Sent: Thursday, August 28, 2014 10:06 AM > To: Richardson, Bruce > Cc: Cyril Chemparathy; dev at dpdk.org > Subject: Re: [dpdk-dev] next releases > > 2014-08-28 08:41, Richardson, Bruce: > > As for rte_rdtsc_precise, I'm not sure about its origins, but I'm > > surprised to see that it does not correspond to the rdtscp instruction. > > Can anyone else comment on this one? I would assume it's designed > > to be used to get more accurate measurements of smaller blocks of > > code that we want to benchmark, since rdtsc works best when timing > > larger blocks (in terms of cycle counts, that is, not source lines :-) ). > > The good thing with git history (and well written commit logs) is that > we can easily get such answer: > http://dpdk.org/browse/dpdk/commit/?id=3314648f83c3dc06d7d9a
Indeed! I had mistakenly assumed that the function was older than the dpdk.org history. My bad on that one, and thanks for the link. :-) > > Bruce, do you know how rdtscp is supported across Intel processors? Sorry, no I don't, and the instruction set manuals only say to check the relevant cpuid bit to see if it's supported. :-(. If the existing code works ok, there is probably no compelling reason to look to change it though. > > -- > Thomas
