3 ms·

Sorry, I agree it's not a great title. I was worried the paper's title was misleading (just sounds like textiles), so I chose a representative statement from th

by mappu 7y ago

Sorry, I agree it's not a great title. I was worried the paper's title was misleading (just sounds like textiles), so I chose a representative statement from the author's abstract + conclusion. The link comes via https://devblogs.microsoft.com/oldnewthing/20191011-00/?p=102989 https://devblogs.microsoft.com/oldnewthing/20191011-00/?p=10... which summarized the PDF as """a fantastic write-up of the history of fibers and why they suck. Of particular note is that nearly all of the original proponents of fibers subsequently abandoned them [...] fibers are basically dead""". By restricting itself to the TIOBE top 10, the paper also misses a discussion of BEAM which successfully offers N:M threading.

dang 7y ago
Oh, in that case let's just switch to the URL to that blog post and let it make its point directly. Changed from http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2018/p1364r0.pdf http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2018/p136... above.
- eloff 7y ago
  I had to scroll through all the comments to find this to understand why the comments don't match the article. I think you should have left it, now it's very confusing.
  - dang 7y ago
    That's why I posted https://news.ycombinator.com/item?id=21230286 https://news.ycombinator.com/item?id=21230286 and pinned it to the top. Experience has shown that switching to a better URL is generally better for discussion, though there can be a lag before the thread catches up.
adev_ 7y ago
I am far of being an Erlang expert. But is not the Erlang concurrency model also N:M threading ? If so, it is also a successful usage of Fibers/green threading in highly concurrent environment.
- bullen 7y ago
  From what I understand Erlang has a naive memory model; so whatever a process does, it cannot share efficiently. It's made to handle 1000s of 1-to-1 calls that all fit individually on one core, not one 1000-to-1000 call that needs to use all cores at the same time. Parallelism without "intra cpu and inter core" forced scope has never been hard, just spin up more machines. Or if I put it this way: "if you don't need parallelism and memory speed between the parallelism enough to encounter cache miss problems, could you as well use separate computers?" If the answer is yes then fibers and coroutines are meaningless. This is the problem of this decade, if we can't solve the bottle neck of cache misses on sharing memory (in parallel on one task across cores efficiently) we have no reason to try and scale the number of cores at all. And if that's true we have hit peak Moore's law for transistor computers; in performance, years ago and in energy efficiency, probably around 8nm. Just to illustrate the problem one last time: Naughty Dog converted it's engine to fibers to allow 60 frames per second, but the controller input to frame latency increased with many frames (because the multiple cores cooperating on each frame meant they have to push the frame back because memory is slow) so the benefit was actually reduced. You get lots of smooth bells and whistles (that look good when you don't play the game) but the only meaningful metric (how fast the character acts on your reactions, which is the definition of gameplay) actually degrades. That said I'm looking forward to TLoU 2 as much as the next guy, but I'm not expecting any technical improvements except visuals.

by mappu 7y ago

dang 7y ago

Oh, in that case let's just switch to the URL to that blog post and let it make its point directly. Changed from http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2018/p1364r0.pdf http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2018/p136... above.

eloff 7y ago
I had to scroll through all the comments to find this to understand why the comments don't match the article. I think you should have left it, now it's very confusing.
- dang 7y ago
  That's why I posted https://news.ycombinator.com/item?id=21230286 https://news.ycombinator.com/item?id=21230286 and pinned it to the top. Experience has shown that switching to a better URL is generally better for discussion, though there can be a lag before the thread catches up.

adev_ 7y ago

I am far of being an Erlang expert. But is not the Erlang concurrency model also N:M threading ? If so, it is also a successful usage of Fibers/green threading in highly concurrent environment.

bullen 7y ago
From what I understand Erlang has a naive memory model; so whatever a process does, it cannot share efficiently. It's made to handle 1000s of 1-to-1 calls that all fit individually on one core, not one 1000-to-1000 call that needs to use all cores at the same time. Parallelism without "intra cpu and inter core" forced scope has never been hard, just spin up more machines. Or if I put it this way: "if you don't need parallelism and memory speed between the parallelism enough to encounter cache miss problems, could you as well use separate computers?" If the answer is yes then fibers and coroutines are meaningless. This is the problem of this decade, if we can't solve the bottle neck of cache misses on sharing memory (in parallel on one task across cores efficiently) we have no reason to try and scale the number of cores at all. And if that's true we have hit peak Moore's law for transistor computers; in performance, years ago and in energy efficiency, probably around 8nm. Just to illustrate the problem one last time: Naughty Dog converted it's engine to fibers to allow 60 frames per second, but the controller input to frame latency increased with many frames (because the multiple cores cooperating on each frame meant they have to push the frame back because memory is slow) so the benefit was actually reduced. You get lots of smooth bells and whistles (that look good when you don't play the game) but the only meaningful metric (how fast the character acts on your reactions, which is the definition of gameplay) actually degrades. That said I'm looking forward to TLoU 2 as much as the next guy, but I'm not expecting any technical improvements except visuals.