IBM Baking Some Nice Optimizations To EXT4's Multi-Block Allocator

IBM engineers have been working through some multi-block allocator improvements for the EXT4 file-system driver. In particular, they aim to address some shortcomings that were discovered when running various tests on IBM POWER hardware with a 64k block size.

The EXT4 multi-block allocator improvements were originally sent out in "request for comments" form back in January while now have been cleaned up and sent out as a formal patch series.

When running FS-Mark with 64 threads, IBM testing is showing results going from around ~5,000 files/sec to ultimately up to around ~30,000 files/sec. Yes, a +500% improvement being reported for their setup and using a 64k block size.

Those interested in more information on this EXT4 multi-block allocator work via this patch series.