14 ms·

the OS X kernel is open source. so why aren't people reading it to figure out where this bug is?

by munin 15y ago

kevingadd 15y ago
Yeah, I'm sure if you just read the Darwin kernel there's a '#define USE_LOTS_OF_MEMORY 1' in there that you can change. The class of problems described in the original post are not the sort of thing you 'just find' by glancing at kernel source code. The problems described sound like they could be an issue of poorly tuned heuristics/thresholds, or necessitate some extra machinery inside the OS X memory manager that isn't there currently. It's not like you can send Apple a pull request on github.
- munin 15y ago
  yes I know, that's the point of my question ;) everyone is all positive about "open source" until they have to dive into a few millions lines of complicated system-level C code and then...
  - wickedchicken 15y ago
    > and then... become immensely employable.
  - RickHull 15y ago
    > yes I know, that's the point of my question ;) It's a facile point. > everyone is all positive about "open source" until they have to dive into a few millions lines of complicated system-level C code and then... Does anyone doubt that 99% of open source users never read a line of the source code which they are using? The point is, they have the opportunity to, and more importantly, the 1% (or whatever) with the skills and resources are able to actually do something about it. If you don't have the ability to change or examine the source code, then there is little incentive to do any runtime analysis which might illuminate the problem.
- jfb 15y ago
  But given enough eyes all bugs are shallow! Are you implying that ESR is full of shit?
xpaulbettsx 15y ago
What are you gonna do about it when you find and fix the bug? You can't run a custom kernel on OS X.
- taligent 15y ago
  Do what normal people do. Tell Apple: http://bugreporter.apple.com http://bugreporter.apple.com
- daniel02216 15y ago
  Yes you can: http://shantonu.blogspot.com http://shantonu.blogspot.com http://objc.id.au/post/10101528120/compiling-the-os-x-10-7-kernel http://objc.id.au/post/10101528120/compiling-the-os-x-10-7-k...
  - xpaulbettsx 15y ago
    None of these posts detail how to actually replace the kernel, only how to build it, nor what happens when Apple ships an update that changes the kernel.
    - comex 15y ago
      You install the kernel by running make install, then copying the stuff in BUILD/dst to /. (If you haven't changed any APIs accessible to kexts, you can get away with just copying mach_kernel.) When Apple ships an update, you compile the new kernel.

the OS X kernel is open source. so why aren't people reading it to figure out where this bug is?

by munin 15y ago

the OS X kernel is open source. so why aren't people reading it to figure out where this bug is?

Yeah, I'm sure if you just read the Darwin kernel there's a '#define USE_LOTS_OF_MEMORY 1' in there that you can change. The class of problems described in the original post are not the sort of thing you 'just find' by glancing at kernel source code. The problems described sound like they could be an issue of poorly tuned heuristics/thresholds, or necessitate some extra machinery inside the OS X memory manager that isn't there currently. It's not like you can send Apple a pull request on github.

munin 15y ago
yes I know, that's the point of my question ;) everyone is all positive about "open source" until they have to dive into a few millions lines of complicated system-level C code and then...
- wickedchicken 15y ago
  > and then... become immensely employable.
- RickHull 15y ago
  > yes I know, that's the point of my question ;) It's a facile point. > everyone is all positive about "open source" until they have to dive into a few millions lines of complicated system-level C code and then... Does anyone doubt that 99% of open source users never read a line of the source code which they are using? The point is, they have the opportunity to, and more importantly, the 1% (or whatever) with the skills and resources are able to actually do something about it. If you don't have the ability to change or examine the source code, then there is little incentive to do any runtime analysis which might illuminate the problem.
jfb 15y ago
But given enough eyes all bugs are shallow! Are you implying that ESR is full of shit?

xpaulbettsx 15y ago

What are you gonna do about it when you find and fix the bug? You can't run a custom kernel on OS X.

taligent 15y ago
Do what normal people do. Tell Apple: http://bugreporter.apple.com http://bugreporter.apple.com
daniel02216 15y ago
Yes you can: http://shantonu.blogspot.com http://shantonu.blogspot.com http://objc.id.au/post/10101528120/compiling-the-os-x-10-7-kernel http://objc.id.au/post/10101528120/compiling-the-os-x-10-7-k...
- xpaulbettsx 15y ago
  None of these posts detail how to actually replace the kernel, only how to build it, nor what happens when Apple ships an update that changes the kernel.
  - comex 15y ago
    You install the kernel by running make install, then copying the stuff in BUILD/dst to /. (If you haven't changed any APIs accessible to kexts, you can get away with just copying mach_kernel.) When Apple ships an update, you compile the new kernel.