A ZSTD-Compressed Linux Kernel Could Be Up Next
The Facebook-developed Zstd compression algorithm was added to the Linux 4.14 kernel and hooked up for Btrfs/Squashfs file-system compression. Support is now being worked on so Zstandard can be used for compressing/decompressing the Linux kernel image.
Nick Terrell of Facebook is proposing support for ZSTD-compressed kernel and ramdisk images. This would add to the list of other algorithms already available like Gzip, XZ, LZ4, and others for dealing with kernel images at boot time.
Terrell found that using ZSTD within the Linux kernel for compression is slightly higher memory use on x86 (192 vs. 64KB) but his results so far have been favorable in performance. Of Zstd/Gzip/XZ/LZ4/LZO/Bzip2, he found Zstd to compress the second best while the decompression speed is the second fastest, but he's still figuring out a better way to test kernel decompression performance itself.
The proposed patches for now can be found on the kernel mailing list. Those wishing to learn more about Zstd itself can visit their project page.