7 ms·
BTW, is there somewhere suitable that I can write-up and publish this information without going to the trouble of a formal academic paper? I spent months also
by abainbridge 8y ago
BTW, is there somewhere suitable that I can write-up and publish this information without going to the trouble of a formal academic paper?
I spent months also learning a few things about how the virtual memory page table, memory controller and DRAM subsystem work. I suspect this will be useful to other people and it would be nice to have a forum where this research could be discussed.
- gpderetta 8y agoA blog post a guess. I would love to read it.
- MaxBarraclough 8y agoTo parrot gpderetta, a blog post is probably best (with a linking HackerNews thread of course). Not sure it would make sense to look for publication in a non-academic technical platform (somewhere like drDobbs.com) but I suppose it's an option.
- petermcneeley 8y agoIf you want to see the actual memory latency you can make the next access depend on the results of the previous. uint32_t checksum = 0; uint32_t prevRes = 0; for (int i = 0; i < 1000000; i++) { unsigned offset = (rand32() ^ prevRes )& (TABLE_SIZE - 1); prevRes = table_ints[offset]; checksum += prevRes ; }
- abainbridge 8y agoYeah, I did that. It took 60ns per iteration, as long as the page table for the pages I was hitting was in cache.