DragonFly's HAMMER2 File-System Picks Up More Performance Optimizations

DragonFlyBSD lead developer Matthew Dillon who also created the HAMMER family of file-systems remains quite busy on filling out the remaining features for HAMMER2 and tuning its performance.

Landing today within the DragonFlyBSD Git code has been the latest HAMMER2 file-system improvements.

First up are fixes including for an allocator race condition and related corruption.

But exciting us and warranting today's post is performance work. This includes supporting an asynchronous flush follow-through when the OS requests it and supporting write-clustering at the device-level if enabled. However, write-clustering is disabled by default with HAMMER2. The performance work also has changes to XOP dispatch. In the end, Matthew Dillon noted, "Significantly improves concurrent filesystem ops and I/O and significantly improves sequential filesystem write I/O."

These HAMMER2 improvements and more will be part of the DragonFlyBSD 5.6 release while those wanting to help test the new file-system driver code right away can enjoy the daily snapshots.