A small but impactful Linux 7.2 kernel optimization skips an unnecessary memset of the iomap struct in iomap_iter() after iteration completes. Discovered by a Bytedance engineer, the change eliminates wasted memory write bandwidth in high-IOPS scenarios, delivering approximately 5% IOPS improvement for EXT4 and XFS filesystems when using NVMe SSDs with io_uring. The gain comes from moving just two lines of code. The same VFS pull request also adds infrastructure for FS-VERITY support on XFS via a post-EOF Merkle tree.
792 Impressions