EROFS Metadata Compression Lands Plus A ~2.5x Speedup For Reading Directories
Merged on Monday were the EROFS file-system updates for Linux 6.17. EROFS continues to be a common read-only file-system choice for some mobile/embedded devices as well as container use-cases.
As part of the merged EROFS code for Linux 6.17 is now supporting metadata compression for even smaller read-only file-system images. EROFS metadata compression is now in place for scoring even smaller image sizes but at the cost of higher I/O latency. There is though support for using different compression algorithms / compression levels if still desiring decent performance with less dramatic space savings.
The EROFS updates for Linux 6.17 also include a separate performance improvement. EROFS now supports readahead for directories in the readdir function to improve performance when reading directories. The patch adding this support noted that the readdir test on a large directory with 12,000 sub-files went from handling 926,385 files per second to 2,380,435.. Or about a 2.5x improvement.
See the EROFS pull request for more details on these changes merged for Linux 6.17.
As part of the merged EROFS code for Linux 6.17 is now supporting metadata compression for even smaller read-only file-system images. EROFS metadata compression is now in place for scoring even smaller image sizes but at the cost of higher I/O latency. There is though support for using different compression algorithms / compression levels if still desiring decent performance with less dramatic space savings.
The EROFS updates for Linux 6.17 also include a separate performance improvement. EROFS now supports readahead for directories in the readdir function to improve performance when reading directories. The patch adding this support noted that the readdir test on a large directory with 12,000 sub-files went from handling 926,385 files per second to 2,380,435.. Or about a 2.5x improvement.
See the EROFS pull request for more details on these changes merged for Linux 6.17.