OS

os-kernel-architecture

Guidance on OS and kernel architecture design trade-offs.

Install

mkdir -p .claude/skills/os-kernel-architecture && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/16284" && unzip -o skill.zip -d .claude/skills/os-kernel-architecture && rm skill.zip

Installs to .claude/skills/os-kernel-architecture

Activation

This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.

Operating-system and kernel architecture decisions: monolithic vs microkernel vs hybrid vs unikernel/exokernel, scheduler design, virtual memory & paging, IPC mechanisms, syscall/ABI boundaries, and interrupt handling. Architect-level trade-offs, not driver implementation. USE WHEN: designing or evaluating an OS/kernel, RTOS-vs-GPOS choice, kernel structure, scheduler/memory/IPC subsystem design, syscall/ABI surface, "monolithic", "microkernel", "unikernel", "exokernel", "scheduler", "virtual memory", "IPC". DO NOT USE FOR: Windows driver implementation (use windows driver skills); app-level concurrency (use language skills); container internals (use `virtualization`).
677 chars✓ has a “when” triggerlonger than Claude Code's old 250-char listing cap (fine on current versions)
Advanced

Key capabilities

  • Evaluate monolithic kernel structures
  • Analyze microkernel designs for isolation and verifiability
  • Assess hybrid kernel architectures
  • Consider unikernel approaches for single-purpose applications
  • Examine exokernel designs for application control
  • Design scheduler, memory management, IPC, syscall/ABI, and interrupt subsystems

How it works

This skill provides a framework for evaluating different OS and kernel architectures by comparing their structures, pros, cons, and suitability for various use cases. It also details key subsystems that must be designed.

Inputs & outputs

You give it
OS/kernel design problem or evaluation request
You get back
Analysis of kernel structure trade-offs and subsystem design recommendations

When to use os-kernel-architecture

  • Comparing monolithic vs microkernel designs
  • Designing kernel subsystems
  • Selecting OS architecture

About this skill

OS / Kernel Architecture

Architect-level decisions for operating systems and kernels.

Kernel structure — the core decision

StructureIdeaProsConsFits
MonolithicAll services in kernel space (Linux)Fast (no IPC for services), matureLarge TCB, a fault can panic the systemGeneral-purpose, performance-first
MicrokernelMinimal kernel; drivers/FS/net as user servers (seL4, QNX)Isolation, verifiability, restartable serversIPC cost on hot pathsSafety/security-critical, high-assurance
HybridMonolithic core + some servers (XNU, NT)Pragmatic balanceAmbiguous boundariesCommercial desktop/mobile OS
UnikernelApp + minimal libOS into one address space (MirageOS)Tiny attack surface, fast bootSingle app, weak isolation withinSingle-purpose cloud/edge appliances
ExokernelKernel only multiplexes hardware; libOS in appMax app controlComplexity pushed to appsResearch / specialized perf

Decision drivers: isolation/assurance vs IPC overhead, TCB size, fault containment, restartability, verification goals (seL4 = formally verified).

Subsystems the architecture must pin down

  • Scheduler: fairness (CFS) vs real-time (RMS/EDF, priority + inheritance to avoid priority inversion) vs throughput (batch). Preemptible vs cooperative. Tickless vs periodic tick. SMP load balancing, CPU affinity, NUMA awareness.
  • Memory management: virtual memory + paging, page table levels, TLB pressure, huge pages, demand paging vs pinned, copy-on-write, NUMA placement, OOM policy. MMU-less (embedded) changes everything.
  • IPC: synchronous rendezvous (seL4/L4) vs async message queues vs shared memory + doorbells. IPC latency is the microkernel make-or-break metric.
  • Syscall/ABI: trap vs syscall instruction, vDSO for hot read-only calls, capability-based vs ambient-authority, ABI stability contract.
  • Interrupts: top-half/bottom-half split, threaded IRQs, interrupt latency and determinism (hard real-time needs bounded latency), MSI/MSI-X.

When to recommend what

  • Need provable isolation / restartable drivers → microkernel (seL4/QNX).
  • Need max throughput, rich ecosystem → monolithic (Linux).
  • Single cloud/edge appliance → unikernel.
  • Hard real-time → RTOS or PREEMPT_RT, EDF/RMS scheduling, bounded IRQ latency (see embedded-rtos).

Load deeper material with fetch_docs("os-kernel-architecture", <topic>) when the knowledge base has it.

When not to use it

  • For Windows driver implementation
  • For app-level concurrency concerns
  • For container internals

Limitations

  • Does not cover Windows driver implementation
  • Does not cover app-level concurrency
  • Does not cover container internals

How it compares

This skill focuses on architect-level decisions for OS and kernel design, providing a structured comparison of different kernel types and their subsystems, rather than low-level implementation details.

Compared to similar skills

os-kernel-architecture side by side with the closest alternatives in the catalog.

SkillInstallsUpdatedSafetyDifficulty
os-kernel-architecture (this skill)02moNo flagsAdvanced
software-architecture3336moNo flagsIntermediate
architect-review1094moNo flagsAdvanced
mcp-builder1363moReviewAdvanced

Try saying

Example prompts that trigger this skill in your AI assistant.

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