A Nice Improvement Coming For Faster Btrfs Zstd Decompression
A Btrfs for-next patch removes a redundant copy in the Zstd decompression path by mapping output directly into page-cache folios. The reported improvement is 7.8% for sequential reads with 4K sectors, 3.6% with 16K sectors, 6.8% with 64K sectors, and about 3% for random 4K reads. It is queued for the Linux 7.4 cycle, so these are pre-merge benchmark results rather than a released-kernel guarantee.
The Phoronix forum thread had 10 responses and 11 reactions; the accessible discussion mostly treated the copy-elimination approach as a useful, narrowly scoped optimization.