5 ms·

Interesting. Is there a place you can point me to, to read up on this issue?

by javert 15y ago

0xABADC0DA 15y ago
From the horse's mouth: http://golang.org/doc/go_faq.html#goroutines http://golang.org/doc/go_faq.html#goroutines When they say "system resources" they mean stack space. It's limited in 32-bit because a stack large enough to be useful takes up too many virtual address space. For instance an 8 MiB stack takes up 1/512 of the 32-bit address space so you can only have max 512 threads, but in 64-bit you can have 33 million (current CPUs limited to 2^48 address space) So they segment the stack in Google Go to get more than some small number of threads. Even though Linux (edit: the kernel) only uses 4k or 8k per thread some OSes have severe limits, so they compound the segmented stack problem (making C interop slow and cumbersome) with userspace threading (M:N). A collection of links why that's a bad idea: http://www.kegel.com/c10k.html#1:1 http://www.kegel.com/c10k.html#1:1 Eventually they'll concede that this wasn't a good idea, but I wouldn't bet on when.
- 4ad 15y ago
  There are many more system resources associated with threads, most of them are more important than mere virtual address space consumption, like context switch time and thread creation time. Linux doesn't use 4k or 8k stack per thread, pthreads default on Linux is 2MB. The only thing that's 4kB or 8kB is the kernel stack which doesn't have anything to do with this (the kernel stack 12kB or 24kB on Windows). You might have heard about this "grow stack on demand" thing, but every OS does it, not only Linux and it's about growing the committed memory, the virtual memory used by a stack is fixed at thread creation. Calling C code is very fast and it's trivial to do from Go, http://golang.org/doc/articles/c_go_cgo.html http://golang.org/doc/articles/c_go_cgo.html. Segmented stacks are available in some C implementations as well. It's not Google Go, it's simply Go, there's not a single Google reference on the page and that's intentional. Looking at your previous posts I see you have an obsession with Google. In short, you have absolutely no idea about what you are talking about and you spread malignant misinformation.
  - adgar 15y ago
    He's a notorious anti-Google troll on Reddit. He adds "Google" to "Go" so that his negative posts will be associated with both Google and Go.
    - X-Istence 15y ago
      There existed a programming language called Go before Google came along with their programming language also named Go. Not that anyone knew of the older Go before the whole naming debacle, but it may not just be anti-Google trolling to refer to it as Google Go. /devils advocate hat off.
      - frou_dh 15y ago
        That one has a Yahoo! style exclamation point ;)
  - 0xABADC0DA 15y ago
    > There are many more system resources associated with threads, most of them are more important than mere virtual address space consumption, like context switch time and thread creation time. I think you should read the M:N scheduling links. I'll leave it at that. > Calling C code is very fast and it's trivial to do from Go, http://golang.org/doc/articles/c_go_cgo.html http://golang.org/doc/articles/c_go_cgo.html. Segmented stacks are available in some C implementations as well. http://golang.org/src/pkg/runtime/cgocall.c http://golang.org/src/pkg/runtime/cgocall.c Read the comment at the top. Hardly trivial. > It's not Google Go, it's simply Go, there's not a single Google reference on the page and that's intentional. Looking at your previous posts I see you have an obsession with Google. ... In short, you have absolutely no idea about what you are talking about and you spread malignant misinformation. Shoot the messenger. Maybe I post from a different account when I am critical of Microsoft, or Apple. Why would that matter to you?
    - agentS 15y ago
      > I think you should read the M:N scheduling links. I'll leave it at that. Of the links in that list, 2 worked for me, and both were from 2002. Not exactly up to date information. Also, Erlang, does something similar w.r.t. to multiplexing multiple processes onto fewer threads, so Go isn't exactly alone in this regard. Even Twisted, and Node use a weaker form of this, where everything runs on one thread. > Read the comment at the top. Hardly trivial. First, the comment's meant for language implementors. You don't need to read this comment to be able to do C interop in Go. Second, this isn't even that complicated... did you imagine C interop with other languages is done in a nice, simple way? Any language needs a way to translate calling conventions from the source to the destination and back when doing interop. And, yes, please stop calling it Google Go. People hardly ever say Microsoft C# or Sun Java or Apple Objective C, or Ericcson Erlang, or Netscape Javascript...

Interesting. Is there a place you can point me to, to read up on this issue?

by javert 15y ago

Interesting. Is there a place you can point me to, to read up on this issue?

From the horse's mouth: http://golang.org/doc/go_faq.html#goroutines http://golang.org/doc/go_faq.html#goroutines When they say "system resources" they mean stack space. It's limited in 32-bit because a stack large enough to be useful takes up too many virtual address space. For instance an 8 MiB stack takes up 1/512 of the 32-bit address space so you can only have max 512 threads, but in 64-bit you can have 33 million (current CPUs limited to 2^48 address space) So they segment the stack in Google Go to get more than some small number of threads. Even though Linux (edit: the kernel) only uses 4k or 8k per thread some OSes have severe limits, so they compound the segmented stack problem (making C interop slow and cumbersome) with userspace threading (M:N). A collection of links why that's a bad idea: http://www.kegel.com/c10k.html#1:1 http://www.kegel.com/c10k.html#1:1 Eventually they'll concede that this wasn't a good idea, but I wouldn't bet on when.

4ad 15y ago
There are many more system resources associated with threads, most of them are more important than mere virtual address space consumption, like context switch time and thread creation time. Linux doesn't use 4k or 8k stack per thread, pthreads default on Linux is 2MB. The only thing that's 4kB or 8kB is the kernel stack which doesn't have anything to do with this (the kernel stack 12kB or 24kB on Windows). You might have heard about this "grow stack on demand" thing, but every OS does it, not only Linux and it's about growing the committed memory, the virtual memory used by a stack is fixed at thread creation. Calling C code is very fast and it's trivial to do from Go, http://golang.org/doc/articles/c_go_cgo.html http://golang.org/doc/articles/c_go_cgo.html. Segmented stacks are available in some C implementations as well. It's not Google Go, it's simply Go, there's not a single Google reference on the page and that's intentional. Looking at your previous posts I see you have an obsession with Google. In short, you have absolutely no idea about what you are talking about and you spread malignant misinformation.
- adgar 15y ago
  He's a notorious anti-Google troll on Reddit. He adds "Google" to "Go" so that his negative posts will be associated with both Google and Go.
  - X-Istence 15y ago
    There existed a programming language called Go before Google came along with their programming language also named Go. Not that anyone knew of the older Go before the whole naming debacle, but it may not just be anti-Google trolling to refer to it as Google Go. /devils advocate hat off.
    - frou_dh 15y ago
      That one has a Yahoo! style exclamation point ;)
- 0xABADC0DA 15y ago
  > There are many more system resources associated with threads, most of them are more important than mere virtual address space consumption, like context switch time and thread creation time. I think you should read the M:N scheduling links. I'll leave it at that. > Calling C code is very fast and it's trivial to do from Go, http://golang.org/doc/articles/c_go_cgo.html http://golang.org/doc/articles/c_go_cgo.html. Segmented stacks are available in some C implementations as well. http://golang.org/src/pkg/runtime/cgocall.c http://golang.org/src/pkg/runtime/cgocall.c Read the comment at the top. Hardly trivial. > It's not Google Go, it's simply Go, there's not a single Google reference on the page and that's intentional. Looking at your previous posts I see you have an obsession with Google. ... In short, you have absolutely no idea about what you are talking about and you spread malignant misinformation. Shoot the messenger. Maybe I post from a different account when I am critical of Microsoft, or Apple. Why would that matter to you?
  - agentS 15y ago
    > I think you should read the M:N scheduling links. I'll leave it at that. Of the links in that list, 2 worked for me, and both were from 2002. Not exactly up to date information. Also, Erlang, does something similar w.r.t. to multiplexing multiple processes onto fewer threads, so Go isn't exactly alone in this regard. Even Twisted, and Node use a weaker form of this, where everything runs on one thread. > Read the comment at the top. Hardly trivial. First, the comment's meant for language implementors. You don't need to read this comment to be able to do C interop in Go. Second, this isn't even that complicated... did you imagine C interop with other languages is done in a nice, simple way? Any language needs a way to translate calling conventions from the source to the destination and back when doing interop. And, yes, please stop calling it Google Go. People hardly ever say Microsoft C# or Sun Java or Apple Objective C, or Ericcson Erlang, or Netscape Javascript...