5 ms·

QNX itself had a hope of becoming mainstream as the core of Blackberry 10 OS. Unfortunately, Blackberry has moved over to Android these days.

jschwartzi 8y ago
QNX is mainstream as hell, just not anywhere you'd expect there to be an OS. It's an RTOS and gets used in automotive, medical, and network technologies where software latency needs to be tightly controlled. You wouldn't use it in the same place you'd use Linux anyway.
- thom 8y ago
  This is true. I suppose I'm just curious about more general (server/desktop/mobile) use cases, because the IPC and scheduling issues the parent mentions must be extremely difficult to predict with a wide array of workloads.
  - lsaferite 8y ago
    I remember using the single disk QNX demo back in the day and being highly impressed with the functionality the crammed into that disk. Sad that it never went anywhere as a desktop/server OS.
    - Animats 8y ago
      I ran QNX as a desktop OS for three years when I was working on a DARPA Grand Challenge vehicle. The vehicle ran QNX, so the development systems did, too. It had an early version of Firefox, the Eclipse IDE, Thunderbird mail, and all the Gnu command line tools. Sadly, QNX under Blackberry no longer offers the desktop environment. And QNX's open source/closed source/open source/closed source transitions angered the development community so much that people stopped offering QNX versions of UNIX/Linux software. The most striking thing about running QNX on the desktop was the absolutely consistent response. It doesn't page, so everything is in memory. Going back to Linux felt so laggy. You pay about a 10%-20% overhead cost for all that interprocess communication. It's not a big deal on modern processors, because when you send a message, the receiving process is running on the same CPU and the data is usually in L1 cache since the sender just put it there. So copying is cheap. Incidentally, all the Boston Dynamics robots run QNX. They're coordinating all those limbs and valves from one CPU. It's not distributed; that would be too uncoordinated. Valve update is at 1KHz; balance update is at 100Hz.
      - beagle3 8y ago
        > And QNX's open source/closed source/open source/closed source transitions angered the development community so much that people stopped offering QNX versions of UNIX/Linux software. Was it ever really open? I can't find copies of any version (regardless of how old)
        Animats 8y ago
        Yes.[1] Source made available in 2007. Source closed without warning after the Blackberry acquisition in 2010. QNX is doing well in automotive.[2] QNX is the part of Blackberry that's making money. [1] http://www.qnx.com/news/pr_2471_1.html http://www.qnx.com/news/pr_2471_1.html [2] http://canada.autonews.com/article/20180622/CANADA/180629921/blackberry-reports-q1-loss-but-qnx-auto-software-division-grows-31 http://canada.autonews.com/article/20180622/CANADA/180629921...
        beagle3 8y ago
        IIRC I wanted to download a copy around 2007, but there was no way to do that unless you were already a licensee. I may not recall correctly, though.
  - jschwartzi 8y ago
    It's really not designed for those use cases though. We were using it for a GUI and or finding was that without constraining the resource usage of the GUI using Adaptive Partitioning user-driven workloads could stomp all over the lower-priority processes. This effectively meant that a poorly-configured system would eventually trip the watchdog due to user input. QNX does include features to control this but you have to know enough about it to realize you want them. And POSIX priorities are not enough to prevent this from happening because they are solving a different problem. You might find it useful in servers where controllable latency is more important than responsiveness, but I wouldn't use it in a user-driven workload like a desktop OS without very carefully configuring it. Out-of-the box it can be very unstable.

jschwartzi 8y ago

QNX is mainstream as hell, just not anywhere you'd expect there to be an OS. It's an RTOS and gets used in automotive, medical, and network technologies where software latency needs to be tightly controlled. You wouldn't use it in the same place you'd use Linux anyway.

thom 8y ago
This is true. I suppose I'm just curious about more general (server/desktop/mobile) use cases, because the IPC and scheduling issues the parent mentions must be extremely difficult to predict with a wide array of workloads.
- lsaferite 8y ago
  I remember using the single disk QNX demo back in the day and being highly impressed with the functionality the crammed into that disk. Sad that it never went anywhere as a desktop/server OS.
  - Animats 8y ago
    I ran QNX as a desktop OS for three years when I was working on a DARPA Grand Challenge vehicle. The vehicle ran QNX, so the development systems did, too. It had an early version of Firefox, the Eclipse IDE, Thunderbird mail, and all the Gnu command line tools. Sadly, QNX under Blackberry no longer offers the desktop environment. And QNX's open source/closed source/open source/closed source transitions angered the development community so much that people stopped offering QNX versions of UNIX/Linux software. The most striking thing about running QNX on the desktop was the absolutely consistent response. It doesn't page, so everything is in memory. Going back to Linux felt so laggy. You pay about a 10%-20% overhead cost for all that interprocess communication. It's not a big deal on modern processors, because when you send a message, the receiving process is running on the same CPU and the data is usually in L1 cache since the sender just put it there. So copying is cheap. Incidentally, all the Boston Dynamics robots run QNX. They're coordinating all those limbs and valves from one CPU. It's not distributed; that would be too uncoordinated. Valve update is at 1KHz; balance update is at 100Hz.
    - beagle3 8y ago
      > And QNX's open source/closed source/open source/closed source transitions angered the development community so much that people stopped offering QNX versions of UNIX/Linux software. Was it ever really open? I can't find copies of any version (regardless of how old)
      - Animats 8y ago
        Yes.[1] Source made available in 2007. Source closed without warning after the Blackberry acquisition in 2010. QNX is doing well in automotive.[2] QNX is the part of Blackberry that's making money. [1] http://www.qnx.com/news/pr_2471_1.html http://www.qnx.com/news/pr_2471_1.html [2] http://canada.autonews.com/article/20180622/CANADA/180629921/blackberry-reports-q1-loss-but-qnx-auto-software-division-grows-31 http://canada.autonews.com/article/20180622/CANADA/180629921...
        beagle3 8y ago
        IIRC I wanted to download a copy around 2007, but there was no way to do that unless you were already a licensee. I may not recall correctly, though.
- jschwartzi 8y ago
  It's really not designed for those use cases though. We were using it for a GUI and or finding was that without constraining the resource usage of the GUI using Adaptive Partitioning user-driven workloads could stomp all over the lower-priority processes. This effectively meant that a poorly-configured system would eventually trip the watchdog due to user input. QNX does include features to control this but you have to know enough about it to realize you want them. And POSIX priorities are not enough to prevent this from happening because they are solving a different problem. You might find it useful in servers where controllable latency is more important than responsiveness, but I wouldn't use it in a user-driven workload like a desktop OS without very carefully configuring it. Out-of-the box it can be very unstable.