87bf54bb43
Add zstd compression and decompression support to SquashFS. zstd is a great fit for SquashFS because it can compress at ratios approaching xz, while decompressing twice as fast as zlib. For SquashFS in particular, it can decompress as fast as lzo and lz4. It also has the flexibility to turn down the compression ratio for faster compression times. The compression benchmark is run on the file tree from the SquashFS archive found in ubuntu-16.10-desktop-amd64.iso [1]. It uses `mksquashfs` with the default block size (128 KB) and and various compression algorithms/levels. xz and zstd are also benchmarked with 256 KB blocks. The decompression benchmark times how long it takes to `tar` the file tree into `/dev/null`. See the benchmark file in the upstream zstd source repository located under `contrib/linux-kernel/squashfs-benchmark.sh` [2] for details. I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. | Method | Ratio | Compression MB/s | Decompression MB/s | |----------------|-------|------------------|--------------------| | gzip | 2.92 | 15 | 128 | | lzo | 2.64 | 9.5 | 217 | | lz4 | 2.12 | 94 | 218 | | xz | 3.43 | 5.5 | 35 | | xz 256 KB | 3.53 | 5.4 | 40 | | zstd 1 | 2.71 | 96 | 210 | | zstd 5 | 2.93 | 69 | 198 | | zstd 10 | 3.01 | 41 | 225 | | zstd 15 | 3.13 | 11.4 | 224 | | zstd 16 256 KB | 3.24 | 8.1 | 210 | This patch was written by Sean Purcell <me@seanp.xyz>, but I will be taking over the submission process. [1] http://releases.ubuntu.com/16.10/ [2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/squashfs-benchmark.sh zstd source repository: https://github.com/facebook/zstd Signed-off-by: Sean Purcell <me@seanp.xyz> Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: Phillip Lougher <phillip@squashfs.org.uk> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| block.c | ||
| cache.c | ||
| decompressor.c | ||
| decompressor.h | ||
| decompressor_multi.c | ||
| decompressor_multi_percpu.c | ||
| decompressor_single.c | ||
| dir.c | ||
| export.c | ||
| file.c | ||
| file_cache.c | ||
| file_direct.c | ||
| fragment.c | ||
| id.c | ||
| inode.c | ||
| lz4_wrapper.c | ||
| lzo_wrapper.c | ||
| namei.c | ||
| page_actor.c | ||
| page_actor.h | ||
| squashfs.h | ||
| squashfs_fs.h | ||
| squashfs_fs_i.h | ||
| squashfs_fs_sb.h | ||
| super.c | ||
| symlink.c | ||
| xattr.c | ||
| xattr.h | ||
| xattr_id.c | ||
| xz_wrapper.c | ||
| zlib_wrapper.c | ||
| zstd_wrapper.c | ||