4 ms·

I once worked at a government job and took my computer into the IT department for an issue. I can't remember anything about the original issue. But I do vividl

by _ea1k 3y ago

I once worked at a government job and took my computer into the IT department for an issue. I can't remember anything about the original issue. But I do vividly remember the help desk trying to figure out one last issue. Some process was consuming all my resources. They never could figure out why "System Idle Process" kept doing that.

sweetjuly 3y ago
A few years ago a similar issue cropped up on macOS where when the device was extremely hot (at least on intel), you'll see kernel_task seemingly using a ton of CPU time. What was actually happening is that the kernel was scheduling an idle thread which just put the CPU to sleep in an effort to lower the temperature beyond what it could achieve with fans and DVFS.
justsomehnguy 3y ago
Back in the day I was asked why it consumes 2 seconds of CPU Time each second. I couldn't answer that at time. Took a bit more years and understanding until I remembered that situation and it was obvious for me.
- lynguist 3y ago
  What’s the answer? One second user time and one second kernel time? Or something completely different?
  - justsomehnguy 3y ago
    What @roelschroeven says. CPU Time is a metric of how much 'real time' was spent on the process, so a single thread running 100% time [on a single core with no HT] would give you a full 'real time' second. System idle 'consumes' all the idle CPU time so if the system is doing nothing it's get a second of CPU Time per execution thread. And there are multiple execution threads on almost anything later than 2005. On my T440 with i3-4010U (2 cores, 4 threads) the System Idle consumes ~3 seconds of CPU Time per second, because there are ton of shit running in the background so the system is never 100% idle.
  - thebruce87m 3y ago
    2 cores?
    - justsomehnguy 3y ago
      Given the time it was probably a full blown, single core CPUs.
  - roelschroeven 3y ago
    It was a dual processor system. The computer I'm using right now has 8 logical processors, and that statistic is incremented by 8 seconds per second: 1 second per logical processor.

by _ea1k 3y ago

sweetjuly 3y ago

A few years ago a similar issue cropped up on macOS where when the device was extremely hot (at least on intel), you'll see kernel_task seemingly using a ton of CPU time. What was actually happening is that the kernel was scheduling an idle thread which just put the CPU to sleep in an effort to lower the temperature beyond what it could achieve with fans and DVFS.

justsomehnguy 3y ago

Back in the day I was asked why it consumes 2 seconds of CPU Time each second. I couldn't answer that at time. Took a bit more years and understanding until I remembered that situation and it was obvious for me.

lynguist 3y ago
What’s the answer? One second user time and one second kernel time? Or something completely different?
- justsomehnguy 3y ago
  What @roelschroeven says. CPU Time is a metric of how much 'real time' was spent on the process, so a single thread running 100% time [on a single core with no HT] would give you a full 'real time' second. System idle 'consumes' all the idle CPU time so if the system is doing nothing it's get a second of CPU Time per execution thread. And there are multiple execution threads on almost anything later than 2005. On my T440 with i3-4010U (2 cores, 4 threads) the System Idle consumes ~3 seconds of CPU Time per second, because there are ton of shit running in the background so the system is never 100% idle.
- thebruce87m 3y ago
  2 cores?
  - justsomehnguy 3y ago
    Given the time it was probably a full blown, single core CPUs.
- roelschroeven 3y ago
  It was a dual processor system. The computer I'm using right now has 8 logical processors, and that statistic is incremented by 8 seconds per second: 1 second per logical processor.