This article explains Linux's memory reclamation mechanisms, covering the role of memory as the system's bloodstream, the three reclamation paths (fast, direct, kswapd), zone watermarks, page cache structures, reverse mapping, and how swap and compression are used to keep the system stable under memory pressure.
This article explains the ZRAM technology in Linux, covering its principles, configuration steps, kernel integration, performance optimizations, and practical use cases for improving memory utilization on embedded devices, Android, and legacy PCs.
Large folios in the Linux kernel combine multiple pages to reduce TLB misses, page faults, and reclamation cost while enabling more efficient compression; they are supported by filesystems like XFS and bcachefs, and recent patches add multi‑size THP, swap‑in/out handling, TAO allocation, NUMA balancing, and debug tools, with OPPO’s production deployment showing performance gains and motivating broader adoption and fragmentation mitigation.
This article explains how Linux memory compression techniques such as zSwap, zRAM, and the Zstandard algorithm reduce I/O pressure, extend flash lifespan, and improve overall system performance, while also covering their drawbacks and step‑by‑step activation procedures.
Memory compression techniques like Linux's zSwap, zRAM, and the zstd algorithm reduce I/O latency and extend RAM capacity by compressing swap pages, offering performance gains while introducing trade‑offs such as CPU overhead and configuration complexity, and this guide explains their principles, advantages, drawbacks, and activation steps.
Linux reduces RAM pressure through three main compression mechanisms—zSwap, which caches compressed pages before writing to swap; zRAM, a RAM‑backed compressed block device; and zCache, a file‑page compressor—each paired with specialized allocators (zsmalloc, zbud, z3fold) and configurable algorithms, offering trade‑offs in speed, ratio, CPU load, and fragmentation.
