Operating Systems / Linux

Virtual memory, paging, address translation, allocation, caching, reclaim, and persistent storage boundaries.

Virtual address spaces, page tables, demand paging, page faults, locality, swap, and why virtual memory is more than 'RAM plus disk'.

Virtual mappings, physical-page allocation, user-space allocators, reclaim, swap, and OOM.

Physical and virtual addresses, paging, segmentation, page tables, and why modern systems primarily rely on paging rather than universal segmentation-plus-paging.

Linux virtual memory, resident pages, page cache, anonymous memory, reclaim, and the role of swap as backing storage rather than virtual memory itself.

Page-replacement goals and classic OPT, FIFO, LRU, LFU, Clock, and working-set ideas, with the distinction between textbook algorithms and real kernels.

How user-space programs enter the kernel to request privileged services, how this differs from an ordinary function call, and why libc wrappers matter.

Blocking, non-blocking, readiness-based multiplexing, signal-driven I/O, asynchronous completion, and Reactor-style server architectures.

How Linux readiness APIs differ in descriptor representation, scanning cost, registration model, and level- vs. edge-triggered behavior.

File descriptors, page cache, buffered and direct I/O, blocking, readiness, and durable writes.