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How IEEE 754 Floating Point Works: Formats, Rounding, and Why 0.1 Is Not Exact

A statement like 0.1 + 0.2 == 0.3 fails in Python, JavaScript, Java, Go, and C for the same reason. None of those languages stored the deci...

Sarthak Bystander 6 Oct, 2026

Latest Posts

How IEEE 754 Floating Point Works: Formats, Rounding, and Why 0.1 Is Not Exact

A statement like 0.1 + 0.2 == 0.3 fails in Python, JavaScript, Java, Go, and C for the same reason. None of those languages stored the deci...

Sarthak Bystander 6 Oct, 2026

How the Linux Buddy and SLUB Allocators Work: Orders, Partial Slabs, and Why malloc Is Not a Page Fault

A driver that calls kmalloc(256, GFP_ATOMIC) from an interrupt handler and a process that calls malloc(256) are not talking to the same al...

Sarthak Bystander 5 Oct, 2026

How NAND Flash and the FTL Work: Pages, Erase Blocks, and Why a Small Write Rewrites a Block

A database that updates a 4 KiB page does not update a 4 KiB cell on the SSD. The host sends a logical block address. The drive's flash ...

Sarthak Bystander 4 Oct, 2026

How Dynamic Linking Works: PLT, GOT, and Why the First Call Is Indirect

A call to puts in a normal C binary is not a direct jump to libc. The machine code in the executable names a procedure-linkage-table stub. ...

Sarthak Bystander 3 Oct, 2026

How fork and Copy-on-Write Work: Page Tables, Shared Pages, and Why the Child Is Not Free

A prefork server that looked cheap in RSS before the first request can double its memory after workers start handling traffic. fork did not...

Sarthak Bystander 2 Oct, 2026

How the Linux VFS Works: Inodes, Dentries, and Why Paths Are Not Files

An open("/var/log/app.log", O_RDONLY) does not hand the kernel a file. It hands the kernel a string. The Virtual File System (VFS...

Sarthak Bystander 1 Oct, 2026

How sendfile and splice Work: Pipe Buffers, Page References, and Why Zero-Copy Is Not Zero Work

A static file server that uses read() into a user buffer and write() onto a socket copies every byte twice through the CPU: page cache to ...

Sarthak Bystander 30 Sept, 2026

How Linux Interrupts Work: Hardware IRQs, Softirqs, and Why Threaded Handlers Exist

A NIC that just received a frame cannot wait for the current process to finish a syscall. The device raises a hardware interrupt. The CPU st...

Sarthak Bystander 29 Sept, 2026

How Linux Signals Work: Pending Masks, Delivery on Return to Userspace, and Why They Are Not Interrupts

A process that spends all its time in a tight userspace loop never notices SIGTERM until the kernel has a chance to put that process back on...

Sarthak Bystander 28 Sept, 2026

How the Linux Page Cache Works: Radix Trees, Writeback, and Why read() Hits DRAM

A process asks for a few bytes from a file. The kernel may return them without asking the storage device for anything at all—not because the...

Sarthak Bystander 27 Sept, 2026

How Futexes Work: Userspace Fast Path, Wait Queues, and Why Mutexes Avoid Syscalls

A mutex that takes a system call on every lock and unlock would dominate a hot critical section. The uncontended case is a few atomic instru...

Sarthak Bystander 25 Sept, 2026