The reading, quizzes, lectures, exams, and labs for this course are all designed around a set of learning objectives:
These learning objectives can be sub-divided into a few basic categories:
| Lect/Lab | Subject | Concept | Issue | Approach | Skill |
|---|---|---|---|---|---|
| 1 | Introduction to Course and Operating Systems |
why study OS mechanism/policy separation interface vs implementation interface contracts modularity/information hiding powerful abstractions appropriate abstraction indirection/deferred binding cohesion opaque encapsulation thinking data structures OS types/history |
layered/hierarchical structure dynamic equilibrium |
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| 2 | Operating Systems and Services |
what is OS basic OS services higher level OS services layers of services APIs and ABIs service protocols |
why functionality implmented in OS OS goals |
subroutines vs system calls |
|
| 3 | Processes |
private resource objects and operations abstracted resources serially reusable resources partitioned resource sharable resource programs and processes process address space process state (elements of) process resources user-mode, supervisor-mode |
fork vs exec |
process implementation copy-on-write |
process operations |
| 4 | Client-Facing Interfaces |
upwards compatability stacks/linkage conventions traps (exceptions) interrupts (async events) traps (syscalls) limited direct execution linkage editing - resolution linkage editing - loading and relocation |
syscalls vs procedure calls |
versioned interfaces context save/restore static libraries shared libraries dynamically loadable libraries Procedure Linkage Table |
signals (exceptions) dlopen(), dlsym() |
| P1A | I/O and IPC |
file APIs |
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| 5 | Scheduling |
metrics: completion time metrics: throughput metrics: response time service level agreement non-preemptive scheduling time sharing time slice |
scheduling goals starvation convoy cost of context switch optimal time slice end-to-end performance graceful degradation |
First In First Out Shortest Job First priority scheduling real time scheduling preemptive scheduling round-robin multi-levelfeedback queues dynamic equilibrium mechanism/policy separation |
|
| 6 | Memory Management |
physical address space virtual address space text segment data segment stack segment shared library segments protected memory access |
memory management goals internal fragmentation external fragmentation common errors |
address space layout stack vs heap allocation variable size allocation malloc vs sbrk memory allocation life cycle coalescing free list design first fit best fit worst fit next fit diagnostic free lists garbage collection |
|
| 7 | Swapping and Relocation |
execution state model process state (model) swap space paged address space page table entry |
relocation problem pool rebalancing |
base/limit relocation segment addressing pool/slab allocation memory compaction swapping paging MMU translation look-aside buffer |
|
| 8 | Demand Paging |
page replacement Temporal Locality Spatial Locality Least Recently Used working set clean/dirty pages |
thrashing paging and segmentation |
demand paging page fault process Belady's Optimal Algorigthm LRU clock algorithm working set clock algorithm page stealing copy on write proactive page laundering |
|
| 9 | Threads and Inter-Process Communication |
thread thread state IPC purpose |
thread motivations IPC goals flow control |
thread stacks user mode implementations stream IPC message IPC shared memory IPC synchronous vs asynchronous IPC |
|
| 10 | Mutual Exclusion |
non-deterministic execution race condition indeterminate results critical section parallelism scenarios |
locking goals correct mutual exclusion |
mutual exclusion atomicity spinning types of locks interrupt disables spin locks |
|
| P2A | Mutual Exclusion |
thread API recognize critical sections pthread_mutex operations pthread_cond operations protect critical section |
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| 11 | Lock Contention and Performance |
reasonable spinning costs of contention granularity convoy common synchronization errors |
compare and swap contention reduction file level locking advisory locking |
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| 12 | Performance |
performance metrics |
goals and challenges performance principles typical causes of performance problems common measurement errors |
load generation traces/logs internal instrumentation end-to-end measurement |
load characterization analysis techniques |
| P2B | Complex Critical Sections (contd) |
malloc APIs profiling |
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| 13 | asynchronous completion |
condition variables locking & event completion |
correct order who to wake up sleep/wakeup races spurrious wakeup |
synchronous requests asynchronous completion asynchronous events waiting lists |
|
| 14 | Higher Level Synchronization Problems |
Semaphores |
bounded buffer problem producer/consumer problem |
binary semaphores using semaphores condition variables using condition variables semaphore implementation CV implementation monitors java synchronization where to serialize |
|
| P2B | Complex Critical Sections (contd) |
malloc APIs profiling |
|||
| 15 | Deadlocks |
Dining Philosophers problem necessary conditions livelock |
deadlock priority inversion |
avoidance reservations prevention detection and recovery |
|
| 16 | I/O Mechanisms |
I/O bus Device Controller disk geometry |
importance of disks disk performance |
polled I/O DMA completion interrupts initiating I/O operations write-back cache write-through cache |
|
| 17 | I/O performance and Programming |
random vs sequential I/O transfer size |
chain scheduling buffered I/O scatter/gather intelligent I/O devices read/write striping write mirroring parity/erasure coding asynchronous parallel I/O polling for asynchronous completions non-blocking I/O asynchronous event notifications |
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| 18 | Files and File Systems |
file semantics file types and attributes data base semantics object semantics key-value semantics |
read after write consistancy goals of file representation goals of free space representation |
BSD file system organization FAT file system organization indexed data extents (I-nodes) linked data extents (FAT) linked free lists (Unix V5) contiguous allocation bit-map free lists (BSD) FAT free list |
|
| 19 | File Name Spaces |
file namespace file name conventions copies vs links symbolic vs hard links |
goals of namespace representation |
BSD directory entries FAT file descriptors |
|
| 20 | File System Performance |
disks and file system design block size & internal fragmentation |
the mount operation file access layers of abstratction dynamically loadable file systems user mode file systems read cache write-through general/special purpose caches how to beat LRU delayed writes write-back cache defrragmentation |
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| 21 | File System Robustness |
causes of file system damage |
detection and repair journaling and recovery meta-data-journaling copy-on-write file systems log structured file systems checksums and scrubbing |
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| 22 | Operatigng System Security |
confidentiality integrity controlled sharing object, agent, principal mediated access revocability trusted computing platform principles of secure design authentication authorization access control lists Linux file protection (ACLS) capabilities unforgeability Linux file descriptors (capabilties) principle of least privilege Role Based Access Control Trojan horses |
challenges |
cryptographic hashes challenge/response authentication Linux principals Linux authentication Linux setuid |
|
| 23 | Introduction to Distributed Systems |
goals RPC RPC stub RPC skeleton RESTful interface principles Marshal/unmarshal |
challenges Deutsch's 7 Falacies RPC interoperability man in the middle attacks |
RPC tool chain XDR reliable communication distributed locks leases distributed transactions |
|
| 24 | Encryption and Secure Sessions |
cryptographic hash unforgeable capabilities |
key security |
at rest encryption symmetric encryption asymmetric encryption public key encryption cryptographic privacy digital signatures public key certificates secure sessions |
|
| 25 | Remote FIle Systems |
local vs cloud client/server model distributed file systems |
remote file system goals |
remote file transfer remote file access peer-to-peer security work tickets distributed authentication/authorization |
|
| 26 | Remote File Systems Performance & Robustness |
immutability reliability availability stateless server protocols idempotent operations ACID Consistency Read-After-Write Consistency Close-Open Consistency |
graceful degradation write latency |
replication and recovery distributed data striping direct client-server communication |
|
| 27 | Multi-Processor and Tightly Compled Systems |
quorum classes of distributed systems Single System Image Non-Uniform Memory Architecture tightly coupled cluster membership |
split-brain cache consistency APIs -> protocols |
distributed consensus scalable distributed systems client-side caching Symmetric Multi-Processor Clustered heart beating partitioned responsibility |
|
| 28 | Loosely Coupled and Cloud Models |
loosely coupled unit of deployment unit of failure/replacement Geographic Disaster Recovery availability zones Single Point of Failure Eventual Consistency BASE semantics |
CAP Theorem |
Horizontally Scaled WAN-scale replication WAN-scale consistency models |
Last updated: 11/15/2023