News › performance
By Zayden R., September 20, 2026
Linux 7.4 introduces a simple yet effective optimization that increases file opening speed by 39%. This improvement, led by developer Mateusz Guzik, reduces unnecessary work in the kernel's do_open() VFS function.
In a noteworthy advancement for the Linux kernel, version 7.4 is set to include an optimization that can increase file opening speeds by approximately 39%. This enhancement, spearheaded by open-source developer Mateusz Guzik, targets the kernel's do_open() VFS function, streamlining the process by eliminating redundant operations. Engineers should find this development particularly relevant as it addresses inefficiencies that have persisted for years.
The optimization focuses on the duplicate directory entry, or 'dentry', involved in translating path components to disk inodes during file opening. In simpler terms, the current process grabs multiple references during the file opening sequence, which Guzik's patch fixes by allowing do_dentry_open() to consume an already-held reference. This change might seem minor, but it results in significant performance gains.
Benchmarking on a 20-core virtual machine using the will-it-scale benchmark revealed that the operations per second increased by 39% when opening the same file in read-only mode. It's somewhat surprising that such an optimization opportunity remained untapped in the Linux kernel for so long.
The patch itself is concise, consisting of roughly three dozen lines of code, and is currently queued into the VFS.git's vfs-7.4.lookup branch. With the optimization flagged for inclusion in the Linux 7.4 release, engineers can expect it to be part of the stable kernel by the end of 2026. This is a solid improvement for those managing high-performance Linux systems, especially where file access speed is critical.