Course audit report

Operating Systems

Done Role: Devops / Sre 3 Findings Operating Systems — Core Concepts And Mechanisms
Auditor Done Market Fit Done Topics Done
Run another role
3 findings · 3 low
Outdated Ch1-2 - Introduction_1_.pptx, Slide 2 (and footer of every slide deck in the course)

What the slide says

Textbook cited as 'Silberschatz, Galvin and Gagne, Operating System Concepts – 9th Edition' (©2013); footer 'Operating System Concepts – 9th Edition' appears on virtually every slide.

Primary source ✓ Source checked

www.os-book.com ↗

Welcome to the Web Page supporting Operating System Concepts, Tenth Edition. This new edition (April 15, 2018), which is published by John Wiley & Sons, is available for purchase…

What to learn instead

Adopt the 10th Edition (2018) of Operating System Concepts. The 10th edition revises terminology (e.g., 'NVM device' alongside HDD), updates examples (drops obsolete Solaris/Mac-OS-X references), and corrects sector-size guidance (512 B or 4,096 B). Update the footer and bibliographic citations accordingly.

Outdated ch4 - Threads.pptx, Slide 12 ('Mac OS X iOS Android'); ch4 - Threads.pptx, Slide 20 ('Common in UNIX operating systems (Solaris, Linux & Mac OS X)'); Ch1-2 - Introduction_1_.pptx, Slide 17 ('POSIX API for POSIX-based systems (including … Mac OS X)')

What the slide says

Slides repeatedly refer to Apple's desktop operating system as 'Mac OS X'.

Primary source ✓ Source checked

www.apple.com ↗

With its debut on Mac, Siri is now on all four Apple software platforms — iOS, macOS, watchOS and tvOS… Apple today previewed macOS Sierra, a major update to the world's most advanced desktop operating system…

What to learn instead

Use the current name 'macOS' (rebranded from OS X / Mac OS X at WWDC 2016 with the release of macOS 10.12 Sierra). Where a historical context is intended, write 'macOS (formerly Mac OS X / OS X)'.

Outdated ch13_ch14_File System.pptx, Slide 17 ('File-System Structure')

What the slide says

'I/O transfers performed in blocks of sectors (usually 512 bytes)'.

Primary source ✓ Source checked

docs.kernel.org ↗

Storage devices may report a physical block size that is bigger than the logical block size (for instance a drive with 4KB physical sectors exposing 512-byte logical blocks to the operating system).

What to learn instead

State that modern storage devices use either 512-byte or 4,096-byte (4 KiB / 'Advanced Format') sectors, and that solid-state / NVM devices essentially always use 4 KiB blocks. (The 10th-edition speaker notes already say this — 'Depending on the disk drive, sector size is usually 512 bytes or 4,096 bytes. NVM devices usually have blocks of 4,096 bytes' — but the slide text was not updated to match.) Also distinguish 'logical block size' (often still 512 B for compatibility) from 'physical block size' (commonly 4 KiB).

This Silberschatz-based undergraduate OS-fundamentals course teaches classical kernel-side concepts (processes, semaphores, scheduling, paging, file allocation) cleanly within its stated depth bound, but every devops_sre skill the market demands at ≥30% (Docker 100%, Bash 100%, Kubernetes 83%, Terraform/CI-CD/AWS 75%, Prometheus/GitHub Actions/on-call 67%, Helm/Datadog 58%, etc.) belongs to the modern container/cloud/observability tooling domain that is explicitly out of this course's scope and has 0% partial coverage in any slide — so no in-domain extensions can legitimately be recommended; these are out-of-domain curriculum-design gaps, not in-course gaps.

No extendable gaps for this role

Stale only flags gaps that the course already partially covers. It won't push you toward Kubernetes when you're sitting in a Unicode course. For devops_sre, every high-frequency market demand is in a different area from what this course actually teaches.

Try a different target role on the run page, or run Stale on a course whose subject area overlaps the role you're aiming for.

What the curriculum actually teaches (38 skills)
  • POSIX system calls (open, read, write, close, fork, exec, wait, exit, kill) · Operating Systems
    Ch1-2 Slide 15: 'On Unix, Unix-like and other POSIX-compatible Operating Systems, popular system calls are open, read, write, close, wait, exec, fork, exit, and kill.'
  • Kernel-mode vs user-mode and the mode bit · Operating Systems
    Ch1-2 Slide 12: 'Dual-mode operation allows OS to protect itself... Mode bit provided by hardware... Some instructions designated as privileged, only executable in kernel mode.'
  • fork()/exec()/wait()/exit() process lifecycle (UNIX) · Operating Systems
    Ch3 Slide 21 speaker notes: 'A new process is created by the fork() system call... one of the two processes typically uses the exec() system call to replace the process's memory space... it can issue a wait() system call to move itself off the ready queue.'
  • Process Control Block (PCB) layout (state, PC, registers, scheduling info, memory-mgmt info, I/O list) · Operating Systems
    Ch3 Slide 10: 'PCB... Process state, Program counter, CPU registers, CPU scheduling information, Memory-management information, Accounting information, I/O status information.'
  • Zombie/orphan processes; init/systemd as orphan reaper · Operating Systems
    Ch3 Slide 29: 'A process that has terminated, but whose parent has not yet called wait(), is known as a zombie process... Traditional UNIX systems addressed this scenario by assigning the init (or systemd) process as the new parent to orphan processes.'
  • IPC: shared memory and message-passing (direct/indirect, sync/async, buffered) · Operating Systems
    Ch3 Slides 30–41: 'Two models of IPC: Shared memory... Message passing'; 'Synchronous / Asynchronous communication'; 'Zero capacity / Bounded / Unbounded' buffers.
  • Bounded-buffer producer–consumer problem · Operating Systems
    Ch3 Slide 33 / Ch6 Slides 15–20: 'Producer-Consumer Problem... bounded-buffer assumes that there is a fixed buffer size... Producer must wait if all buffers are full.'
  • POSIX Pthreads, Windows threads, Java threads APIs · Operating Systems
    Ch4 Slide 19–20: 'Three main thread libraries are in use today: POSIX Pthreads, Windows, and Java'; 'A POSIX standard (IEEE 1003.1c) API for thread creation and synchronization.'
  • Java Runnable interface, Thread.start(), Java Executor framework / thread pools · Operating Systems
    Ch4 Slides 26–34: 'Implementing the Runnable interface... Calling start()'; 'Java also allows thread creation around the Executor interface'; 'Three factory methods for creating thread pools in Executors class.'
  • Multithreading models (many-to-one, one-to-one, many-to-many) · Operating Systems
    Ch4 Slides 14–17: 'Many-to-One Model... One-to-One Model... Many-to-Many Model.'
  • Concurrency vs. parallelism; data vs. task parallelism · Operating Systems
    Ch4 Slide 10–11: 'A system is parallel if it can perform more than one task simultaneously. A concurrent system supports more than one task by allowing all the tasks to make progress'; 'Data parallelism... Task parallelism.'
  • Implicit threading frameworks named (OpenMP, Grand Central Dispatch, Intel TBB, Fork-Join) · Operating Systems
    Ch4 Slide 31: 'Five alternative methods explored: Thread Pools, Fork-Join, OpenMP, Grand Central Dispatch, Intel Threading Building Blocks.'
  • CPU scheduling algorithms: FCFS, SJF, SRTF, Priority, Round-Robin · Operating Systems
    Ch5 Slides 13–28: 'First-Come, First-Served (FCFS)'; 'Shortest-Job-First (SJF)... Shortest-Remaining-Time-First (SRTF)'; 'Round Robin (RR) Algorithm... time quantum q.'
  • Multilevel queue and multilevel feedback queue scheduling; aging · Operating Systems
    Ch5 Slides 36–41: 'A multilevel queue scheduling algorithm partitions the ready queue into several separate queues'; 'Multilevel Feedback Queue: A process can move between the various queues... Aging.'
  • Preemptive vs non-preemptive scheduling; dispatcher and dispatch latency · Operating Systems
    Ch5 Slides 8–10: 'Virtually all modern operating systems including Windows, MacOS, Linux, and UNIX use preemptive scheduling algorithms'; 'Dispatcher module gives control of the CPU... Dispatch latency.'
  • Race conditions and the critical-section problem (mutual exclusion, progress, bounded waiting) · Operating Systems
    Ch6 Slide 23: 'Mutual Exclusion... Progress... Bounded Waiting - A bound must exist on the number of times that other processes are allowed to enter their critical sections.'
  • Peterson's software-based mutual-exclusion algorithm · Operating Systems
    Ch6 Slides 27–34: 'Software-based Solution: Peterson's Solution... The two processes share two variables: int turn; boolean flag[2].'
  • Memory barriers / memory-ordering models (strongly vs weakly ordered) · Operating Systems
    Ch6 Slide 36: 'Strongly ordered – where a memory modification of one processor is immediately visible... A memory barrier is an instruction that forces any change in memory to be propagated to all other processors.'
  • Atomic hardware instructions: test_and_set() and compare_and_swap() (CAS); spinlocks · Operating Systems
    Ch6 Slides 39–46: 'Test-and-Set() instruction... Compare-and-Swap() instruction'; 'while (test_and_set(&lock)) ... This is called a spinlock.'
  • Atomic variables built on CAS · Operating Systems
    Ch6 Slide 48–49: 'an atomic variable that provides atomic (uninterruptible) updates on basic data types... void increment(atomic_int *v)... compare_and_swap(v,temp,temp+1).'
  • Mutex locks (acquire/release) and Dijkstra counting/binary semaphores (P/V, wait/signal) · Operating Systems
    Ch6 Slides 50–55: 'mutex lock... acquire() and release()'; 'Semaphore S – integer variable... wait() and signal()... Originally called P() and V().'
  • Deadlock characterization (mutual exclusion, hold-and-wait, no preemption, circular wait) · Operating Systems
    Ch8 Slide 8: 'Deadlock can arise if four conditions hold simultaneously... Mutual exclusion... Hold and wait... No preemption... Circular wait.'
  • Resource-allocation graph and wait-for graph cycle detection · Operating Systems
    Ch8 Slides 9–12, 21–22: 'Resource-Allocation Graph... request edge / assignment edge'; 'Maintain wait-for graph... Periodically invoke an algorithm that searches for a cycle.'
  • Deadlock prevention / avoidance / detection / recovery (incl. resource ordering, victim selection, rollback) · Operating Systems
    Ch8 Slides 15–25: 'Deadlock prevention'; 'Impose a total ordering of all resource types'; 'Recovery from Deadlock: Process/Thread Termination'; 'Resource Preemption: Selecting a victim... Rollback... Starvation.'
  • Address binding (compile/load/execution time); base & limit registers; MMU and relocation register · Operating Systems
    Ch9 Slides 8–13: 'Address binding of instructions and data to memory addresses can happen at three different stages: Compile time... Load time... Execution time'; 'memory-management unit (MMU).'
  • Static vs. dynamic linking; shared libraries / DLLs · Operating Systems
    Ch9 Slide 15–16: 'Static linking... Dynamic linking – linking postponed until execution time... Dynamically linked libraries (DLLs)... shared libraries... Windows and Linux systems.'
  • Contiguous allocation: first-fit / best-fit / worst-fit; internal vs external fragmentation; 50% rule; compaction · Operating Systems
    Ch9 Slides 23–26: 'First-fit... Best-fit... Worst-fit'; 'External Fragmentation... Internal Fragmentation'; '50-percent rule'; 'Reduce external fragmentation by compaction.'
  • Segmentation (segment table with base/limit) · Operating Systems
    Ch9 Slide 31: 'Segment Table... base – contains the starting physical address... limit – specifies the length of the segment.'
  • Paging (page number/offset, page table, frame table) · Operating Systems
    Ch9 Slides 35–38: 'Divide physical memory into fixed-sized blocks called frames... Set up a page table to translate logical to physical addresses'; 'Extract the page number p and use it as an index into the page table.'
  • Demand paging; valid–invalid bit; page-fault handling · Operating Systems
    Ch10 Slides 9–14: 'demand paging... pages are loaded only when they are demanded'; 'valid–invalid bit'; 'Steps in Handling Page Fault.'
  • Page replacement: FIFO, OPT, LRU; Belady's anomaly; modify (dirty) bit · Operating Systems
    Ch10 Slides 28–36: 'First-In-First-Out (FIFO)'; 'Optimal Algorithm'; 'Least Recently Used (LRU)'; 'Belady's anomaly'; 'modify bit (or dirty bit).'
  • Free-frame list and zero-fill-on-demand · Operating Systems
    Ch10 Slide 17: 'Most operating systems maintain a free-frame list... zero-fill-on-demand -- the content of the frames zeroed-out before being allocated.'
  • File concept, attributes, operations (create/open/read/write/seek/close/delete/truncate) · Operating Systems
    Ch13 Slides 4–7: 'File Attributes: Name, Identifier, Type, Location, Size, Protection, Time...'; 'Operations: Create... Write... Read... Reposition within file – seek... Delete... Truncate.'
  • Sequential vs direct access; IBM ISAM indexing · Operating Systems
    Ch13 Slides 11–14: 'Sequential Access... Direct Access – Random Access to any file block'; 'IBM indexed sequential-access method (ISAM).'
  • Layered file-system architecture (logical FS, file-organization, basic FS, I/O control, device driver) · Operating Systems
    Ch13/14 Slide 18: 'Application Programs / Logical File System / File-Organization module / Basic File System / I/O Control / Device driver.'
  • Specific file systems named: FAT, FAT32, NTFS, UFS, FFS, ext3, ext4, ZFS, GoogleFS, FUSE, ISO 9660 · Operating Systems
    Ch13/14 Slide 19: 'CD-ROM is ISO 9660; Unix has UFS, FFS; Windows has FAT, FAT32, NTFS... Linux... ext3 and ext4... ZFS, GoogleFS, Oracle ASM, FUSE.'
  • On-disk structures: boot block / superblock / FCB / inode; NTFS master file table · Operating Systems
    Ch14 Slide 20: 'Boot Control Block... Volume Control Block... In UFS, this is called a superblock. In NTFS, it is stored in the master file table'; 'inode... data structure in a Unix-style file system.'
  • File allocation methods: contiguous, linked (FAT), indexed · Operating Systems
    Ch14 Slides 22–28: 'Contiguous allocation'; 'Linked allocation – each file is a linked list of disk blocks... use of a FAT (File Allocation Table)'; 'Indexed allocation.'

No prescriptions are issued. The Market-fit agent surfaced gap_count = 0 in-domain gaps: every devops_sre skill the market demands at ≥ 30% frequency (Docker 100%, Bash 100%, Git 92%, Python 92%, Kubernetes 83%, Linux-admin 83%, Monitoring 83%, CI/CD 75%, Terraform 75%, AWS 75%, Go 67%, GitHub Actions 67%, On-call 67%, Prometheus 67%, Helm 58%, Datadog 58%, Jenkins 50%, Grafana 50%, SLOs/SLIs 50%, Ansible 50%, GitLab CI 42%, ArgoCD 42%, Vault 42%, Incident Response 42%) sits in the modern container / cloud / observability tooling domain that has 0% partial coverage anywhere in the Silberschatz-based slide deck. Under Rule 1 (each prescription must extend a partially-covered topic with a citable slide) and Rule 2 (respect the depth bound, which excludes containers/virtualization internals, distributed systems, and hands-on sysadmin labs), none of these market demands can be legitimately mapped onto an existing slide as an extension — they would each require introducing a wholly new topic into a course whose stated intent is classical OS concepts and algorithm-level reasoning.

These top market prescriptions close 0% of the devops_sre market gap from within this course. This is the honest answer: the gap is a curriculum-design gap (the program lacks a Cloud / Containers / SRE-tooling course), not an in-course gap. Topics that *could* be motivated from existing slide content — e.g., 'orphan reaping' → PID 1 in containers, 'mode bit + privileged instructions' → container/VM isolation, 'demand paging + dirty bit' → cgroup memory pressure, 'semaphores' → distributed locks — are all bridge analogies, not market-demanded skills in their own right; pretending they discharge the Docker/K8s/Terraform/Prometheus demand would be scope drift and is rejected under Rule 3. Recommend the program add a separate 'Cloud Infrastructure & SRE' course rather than overload Operating Systems.