EXT4 Reworks Fast Commit Handling & Faster Directory Hash Computation
The EXT4 file-system improvements were merged today for Linux 7.2 with some enticing optimizations.
EXT4 in Linux 7.2 brings a significant rework to its fast commit mechanism to avoid locking contention and deadlocks. EXT4 fast commits are the file-system's hybrid journaling functionality to speed up operations by recording specific delta changes to the metadata in order to avoid full metadata writes. Fast commits can be useful for lowering fsync latency and more efficient performance overall.
Li Chen reworked the fast commit code for addressing locking contention possibilities and deadlocks. For those interested in all the technical details involved can see this patch series.
The other notable change is a performance optimization for directory hashing computations. The optimization is processing input in four-byte chunks and removing function pointers. Cleaning up the EXT4 str2hashbuf code reduces overhead and is delivering around a 2x improvement on longer inputs over the existing byte-by-byte approach for this function used for directory hashing computations.
These EXT4 improvements plus some fixes are all spelled out with today's Git merge for Linux 7.2.
EXT4 in Linux 7.2 brings a significant rework to its fast commit mechanism to avoid locking contention and deadlocks. EXT4 fast commits are the file-system's hybrid journaling functionality to speed up operations by recording specific delta changes to the metadata in order to avoid full metadata writes. Fast commits can be useful for lowering fsync latency and more efficient performance overall.
Li Chen reworked the fast commit code for addressing locking contention possibilities and deadlocks. For those interested in all the technical details involved can see this patch series.
The other notable change is a performance optimization for directory hashing computations. The optimization is processing input in four-byte chunks and removing function pointers. Cleaning up the EXT4 str2hashbuf code reduces overhead and is delivering around a 2x improvement on longer inputs over the existing byte-by-byte approach for this function used for directory hashing computations.
These EXT4 improvements plus some fixes are all spelled out with today's Git merge for Linux 7.2.