https://nalar.dev/tags/madvise/ Recent content in Madvise on Nalar Hugo en-us Sat, 19 Sep 2026 00:00:00 +0000 https://nalar.dev/madv-free-marks-anonymous-pages-for-lazy-reclaim/ Sat, 19 Sep 2026 00:00:00 +0000 https://nalar.dev/madv-free-marks-anonymous-pages-for-lazy-reclaim/ <p><code>MADV_FREE</code> does not immediately replace a private anonymous page with zeros. It marks eligible pages as disposable, allowing Linux to reclaim them later. Until reclaim actually occurs, existing bytes can remain observable. A write before reclaim cancels the disposable state for the affected page.</p> <p>That timing makes <code>MADV_FREE</code> distinct from advice that immediately changes the process-visible state of a range. It is a lazy reclamation contract: the application declares that old contents are expendable, while the kernel chooses when physical memory is recovered.</p>