What are CPU "C-states" and how to disable them if needed?

Solution Verified - Updated -

Issue

  • What are C-states, cstates, or C-modes?
  • How can I disable processor sleep states?
  • How to prevent the kernel to override the BIOS C-state option?
  • Is intel_idle.max_cstate=0 required to disable CPU C-states?

Environment

  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 5

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