Codacoda
Back to Academy

process thread

Context Switching

Context switching is the mechanism by which the OS saves the state of a currently running process or thread and restores the state of the next one to run. This includes saving and loading registers, program counter, stack pointer, and memory mappings. Context switches are necessary for multitasking but introduce overhead — the CPU does no useful work during the switch itself, so minimizing unnecessary switches is key to performance.

Use Cases

  • •Tuning thread pool sizes to reduce excessive context switching overhead in high-throughput servers
  • •Understanding why too many goroutines or green threads can degrade performance
  • •Diagnosing high CPU usage caused by frequent context switches rather than actual computation
  • •Optimizing batch processing by grouping similar work to minimize switching between different tasks

Visualization

CONCEPTexecutingCPUexecuting...Process APC: 0x4020Regs: [r1, r2, r3]Process BPC: 0x8010Regs: [r4, r5, r6]OS Kernel (Scheduler)
Speed:1x
Context switching: The CPU can only run one process at a time. The OS rapidly switches between them.Step 1 / 8

Implementation

Output

Click "Run Code" to see output...