LZ4 Support Revised For Faster Restore From Linux Hibernation

Published originally back in October were a set of patches for allowing different compression algorithms for the Linux hibernation image to yield faster restore times. That work -- focused on LZ4 compression support -- has been revised as it works toward the mainline kernel.

This work out of Qualcomm is about replacing the Linux hibernation's code of explicit LZO API use with the generic crypto APIs and in turn allowing LZ4 to be optionally used for compressing the hibernation image.

By default LZO would be the preferred compression algorithm but via a "hib_compression=lz4" boot option would allow using LZ4 compression. The engineers found that the restore time with LZO was around 4.4 seconds but dropped to around 3.8 seconds when using LZ4, with the decompression rate jumping from 335 MB/s to 501 MB/s. The downside though is the LZ4 compressed image is slightly larger than LZO.

Those interested in this effort for faster hibernation restore performance on Linux systems can find the v2 patches via the kernel mailing list.