This document provides an overview of Linux discard support for SSDs, including benchmark results and the current status. It discusses how discard works at the block layer and is exposed via the BLKDISCARD ioctl. It also covers periodic discard support implemented in various file systems like ext4 and btrfs. Benchmark results show that discard can provide significant performance improvements for filesystem operations and mitigate SSD performance degradation over time. Utilities like fstrim have been developed to invoke batched discard on mounted filesystems.