tzyt's Blog

Notes on xv6 Lab 11 mmap, covering virtual-memory-area tracking, lazy page faults, file-backed mappings, munmap, and process cleanup.

Notes on xv6 Lab 10 file systems, extending inode block addressing for large files and implementing symbolic links with correct system-call behavior.

Notes on xv6 Lab 9 locks, reducing contention in the memory allocator and buffer cache through per-CPU free lists and hashed buffer buckets.

Introduces the Runge–Kutta method for solving ordinary differential equations numerically, including formulas, errors, and experimental results.

Notes on xv6 Lab 8 networking, explaining E1000 descriptor rings and registers and implementing packet transmission and reception in the driver.

Notes on xv6 Lab 7 multithreading, implementing user-level thread switching and studying POSIX threads, synchronization, and barriers.

Notes on xv6 Lab 6 copy-on-write fork, covering shared mappings, page-fault copying, reference counts, uvmcopy, and copyout.

Notes on xv6 Lab 5 lazy page allocation, removing eager sbrk allocation, handling page faults, and passing lazy-allocation and user tests.

Notes on xv6 Lab 4 traps, covering RISC-V assembly, stack backtraces, timer alarms, trap handling, and restoring interrupted execution.

Solutions to several CodeChef Starters 48 problems, explaining the key observations, algorithms, complexity, and C++ implementations.

Solutions to Codeforces 1705 B, C, and D1, explaining greedy array operations, copied-string position mapping, and colored-tower construction.

Solutions to Codeforces 1705 C and D, covering reverse mapping of copied-string queries and the feasibility and minimum cost of binary-string changes.