https://miliucci.org/tags/mglru/Recent content in Mglru on Alessandro MiliucciHugoen-gb© Alessandro MiliucciThu, 09 Jul 2026 00:00:00 +0000https://miliucci.org/post/mongodb-linux-7-2-mglru-performance/Thu, 09 Jul 2026 00:00:00 +0000https://miliucci.org/post/mongodb-linux-7-2-mglru-performance/<p>Linux 7.2 includes a series of patches on its MultiGen-LRU algorithm, allowing a MongoDB performance gain for free under some workloads. This post provides a brief explanation of how Linux memory pages work, as well as the MongoDB-related MGLRU changes.</p> <h2 id="linux-memory-pages-primer">Linux Memory Pages Primer</h2> <blockquote> <p>Warning: This is a simplified explanation, if you want to go deeper <a href="https://www.kernel.org/doc/html/latest/admin-guide/mm/concepts.html">start from here</a>.</p></blockquote> <p>Reading files from disks is an expensive and slow activity. For this reason, when Linux accesses a file for the first time, it puts the file&rsquo;s data in in-memory <em>pages</em>. A page is an abstraction that acts like a cache: if you need the same file content again, it will be served from the memory, skipping the slow disk access.</p>