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With DragonFly's architecture being designed with multiprocessing and clustering in mind, how does it fare (relative to Linux and other BSDs) in modern environm

by agar 8y ago

With DragonFly's architecture being designed with multiprocessing and clustering in mind, how does it fare (relative to Linux and other BSDs) in modern environments with many-core CPUs, horizontally-scalable architectures, reliance on VM-based workloads, and containerization? I would think it would really shine, but haven't seen comparisons - or much market uptake. Wouldn't significant advantages result in lower costs (e.g., fewer CPUs needed because of higher performance per core due to lower OS overhead) and therefore economics would drive greater use? If it hasn't, why not?

arca_vorago 8y ago
I did a little testing about ~4 years ago and found most of the speed increases were in the netstack, but I didn't do any computational testing either. As for your last question, I think largely due to the fact that it's just not mainstream yet.
gh02t 8y ago
I'm not an expert on DragonFly, but from what I know it's design differences aren't really that radical. It differs substantially from FreeBSD, but it's not like a fundamental re-imagining optimized for SMP. Performance is a bit better in some places, and about the same in others. I do think DragonFly is neat and quite interesting, but I suspect it didn't gain as much momentum because the community behind BSD is already small and reluctant to fracture without stronger reasons. It's worth noting that this is not like spinning off a new Linux distro where you're ultimately just repackaging different variations of the same basic OS - DragonFly is effectively an entirely different OS since the kernel is significantly different. Slightly out of date, but still relevant benchmarks: https://www.phoronix.com/scan.php?page=article&item=freebsd11-beta-benchmarks&num=1 https://www.phoronix.com/scan.php?page=article&item=freebsd1...
- agar 8y ago
  Thanks, I took a look through that and most (all?) of the benchmarks seemed to be fairly traditional tasks, some not even highly threaded. I guess I'm wondering if complex, multi-box, cloud-scale workloads have any advantage on Dragonfly - or if the optimizations for clustering are in such a narrow band of use cases that modern architectures have passed it by just through brute force. There's an irony here, in that Matt Dillon was an ex-Amiga hacker (IIRC, some of Dragonfly's architectural choices were inspired by the Amiga). Anyway, the Amiga's linear memory, co-processor-driven architecture was ridiculously more elegant than the PC's segmented memory, CPU-bound approach. Didn't matter though, a huge investment in working around the PC's limitations led to its market dominance. So, if massive technical accommodations for less efficient OS architectures end up marginalizing Dragonfly, it would be a bit of history repeating itself. And I'm sure the irony wouldn't be lost on Mr. Dillon.
walkingolof 8y ago
Phoronix has done some benchmarks vs Linux https://www.phoronix.com/scan.php?page=article&item=dragonfly-48-tests&num=1 https://www.phoronix.com/scan.php?page=article&item=dragonfl...
ianai 8y ago
I’d bet it’s nearly nowhere. It doesn’t have the driver support of Linux.

by agar 8y ago

arca_vorago 8y ago

I did a little testing about ~4 years ago and found most of the speed increases were in the netstack, but I didn't do any computational testing either. As for your last question, I think largely due to the fact that it's just not mainstream yet.

gh02t 8y ago

I'm not an expert on DragonFly, but from what I know it's design differences aren't really that radical. It differs substantially from FreeBSD, but it's not like a fundamental re-imagining optimized for SMP. Performance is a bit better in some places, and about the same in others. I do think DragonFly is neat and quite interesting, but I suspect it didn't gain as much momentum because the community behind BSD is already small and reluctant to fracture without stronger reasons. It's worth noting that this is not like spinning off a new Linux distro where you're ultimately just repackaging different variations of the same basic OS - DragonFly is effectively an entirely different OS since the kernel is significantly different. Slightly out of date, but still relevant benchmarks: https://www.phoronix.com/scan.php?page=article&item=freebsd11-beta-benchmarks&num=1 https://www.phoronix.com/scan.php?page=article&item=freebsd1...

agar 8y ago
Thanks, I took a look through that and most (all?) of the benchmarks seemed to be fairly traditional tasks, some not even highly threaded. I guess I'm wondering if complex, multi-box, cloud-scale workloads have any advantage on Dragonfly - or if the optimizations for clustering are in such a narrow band of use cases that modern architectures have passed it by just through brute force. There's an irony here, in that Matt Dillon was an ex-Amiga hacker (IIRC, some of Dragonfly's architectural choices were inspired by the Amiga). Anyway, the Amiga's linear memory, co-processor-driven architecture was ridiculously more elegant than the PC's segmented memory, CPU-bound approach. Didn't matter though, a huge investment in working around the PC's limitations led to its market dominance. So, if massive technical accommodations for less efficient OS architectures end up marginalizing Dragonfly, it would be a bit of history repeating itself. And I'm sure the irony wouldn't be lost on Mr. Dillon.

walkingolof 8y ago

Phoronix has done some benchmarks vs Linux https://www.phoronix.com/scan.php?page=article&item=dragonfly-48-tests&num=1 https://www.phoronix.com/scan.php?page=article&item=dragonfl...

ianai 8y ago

I’d bet it’s nearly nowhere. It doesn’t have the driver support of Linux.