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A comment on Satya Nadella just fixed Microsoft’s biggest problem. Parent comment

Re:Satya Nadella just fixed Microsoft’s biggest problem by PeCaN on Friday July 15, 2016 @12:32PM (#12102147)
Yikes! NT kernel is far far far better designed than any * nix¹. POSIX is an API (and not a very good one), not a kernel type anyway. Windows has had a POSIX layer for a while. The NT kernel actually has its own API that both the Win32 and POSIX APIs are implemented on top of.

Why is NT better than * nix (particularly Linux)? Two areas mainly:

- Virtual memory

This one's pretty obvious if you've ever written a malloc. Compare VirtualAlloc² with the mess of mmap/madvise/mprotect. I'm not even sure you can get the nice explicit reserve/commit of Windows with pure POSIX APIs.

Linux in particular used to have a very questionable virtual memory implementation³, but I suspect it's been much improved.

NT can demand-page kernel memory; Linux kills processes if the kernel needs memory.

- Async I/O

Here's how platforms do async I/O:

POSIX: You don't.⁴

Linux: Sleep. Wait for the kernel to wake you up when something happens so you can yell “IS ANYONE READY YET? HOW ABOUT NOW?!” at your file descriptors.

FreeBSD: Like Linux, but the API is less stupid.

Windows: Tell the kernel to run a callback when an I/O operation completes.

Personally I'm really excited for ReactOS. Linux is a 1970s kernel design.

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¹ Well, Solaris and DragonFlyBSD have a lot of good ideas and good implementation.

² https://msdn.microsoft.com/en-us/library/windows/desktop/aa3...

³ https://lwn.net/1999/0121/a/vmreview.html

⁴ Okay okay, you have select(2) and poll(2), but then you're using select and poll.

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Re:Satya Nadella just fixed Microsoft’s biggest problem by amaks on Friday July 15, 2016 @07:41PM (#12104508)
> Linux in particular used to have a very questionable virtual memory implementation³, but I suspect it's been much improved.

The document you're referencing is written in 1999. I suspect a lot has changed since then.

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Re:Satya Nadella just fixed Microsoft’s biggest problem by amaks on Friday July 15, 2016 @07:42PM (#12104510)
Also, nobody is using select and poll in Linux these days, epoll is the way to go.
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Re:Satya Nadella just fixed Microsoft’s biggest problem by PeCaN on Friday July 15, 2016 @09:09PM (#12104753)
> Linux: Sleep. Wait for the kernel to wake you up when something happens so you can yell “IS ANYONE READY YET? HOW ABOUT NOW?!” at your file descriptors.

> FreeBSD: Like Linux, but the API is less stupid.

Yeah, I covered epoll (and kqueue, which also applies to Solaris and OS X).

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