How Computers Work
init/systemd
PID 1, root of the process tree
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Processes Threads and the KernelHow Computers WorkMore terms from this board
- context switchsave one thread's state, load another's (~µs + cache cost)
- fork/execclone a process / replace its program
- kernelthe privileged core of the OS
- MMU + page tablethe translator
- namespaces + cgroupsthe kernel features that make a container
- page (~4KB) / frameunit of virtual / physical memory
- page faulttouched a not-in-RAM page
- PIDprocess id
- preemptioninterrupting a thread on its time slice
- processisolated running program (own address space)
- schedulerpicks who runs
- swappaging RAM to disk
- syscalluser code trapping into the kernel for a privileged op
- threadan execution unit sharing a process's memory
- user vs kernel mode (ring 3/0)restricted vs full hardware access