https://sankethbk.github.io/blog/tags/page-cache/Recent content in Page Cache on Sanketh's BlogHugo -- 0.163.3en-usSun, 05 Jul 2026 00:00:00 +0000https://sankethbk.github.io/blog/posts/operating-systems/linux/2026-07-05-page-cache/Sun, 05 Jul 2026 00:00:00 +0000https://sankethbk.github.io/blog/posts/operating-systems/linux/2026-07-05-page-cache/<h2 id="the-linux-page-cache--page-writeback">The Linux Page Cache &amp; Page Writeback</h2> <p><strong>The Core Concept:</strong> Disk access is measured in milliseconds; RAM access is measured in nanoseconds. To bridge this massive performance gap, Linux dynamically uses free physical RAM to cache blocks of disk data.</p> <p>This relies on <strong>temporal locality</strong>: the computing principle that if data is accessed once, it is highly likely to be accessed again very soon.</p> <h3 id="1-reading-from-disk">1. Reading from Disk</h3> <p>The cache is granular; Linux caches specific pages of files based on what you actually access, not whole files by default.</p>