Comment by forrestthewoods
8 hours ago
> Agreed that the odd spikes don't matter, that's why I didn't bother discussing them
That was sarcasm =P Those spikes are very curious and the choice of presentation makes them seem like noise but there is something there that should be investigated further imho. In the graph it looks like noise. I mean it’s just 1ns. But a 2x throughput difference isn’t noise! Thats huge! Very curious.
> Not sure I quite follow what you're saying about mmap on Linux vs Mac
Your 4th conclusion is “On Linux, random order starts getting even slower for arrays over a gigabyte, becoming more than 50x slower than first-to-last order; in contrast, random order on the MacBook seems to just level out as long as everything fits in RAM.”. That doesn’t make sense. There shouldn’t be any OS difference here.
Gotcha, sorry for not picking up on the sarcasm. Yeah, I mean, I didn't really bother running the experiments many times for the smaller array sizes, so it could potentially be interesting to see if those artifacts persist when poked.
Could you clarify why there shouldn't be an OS difference? I was under the impression that it's the OS that handles how swap space is implemented (which was used by the first set of experiments), as well as how memory-mapped files are implemented (which was used by the second set of experiments). Am I mistaken about that?