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e7cdb60fd2
Pull zstd support from Chris Mason:
"Nick Terrell's patch series to add zstd support to the kernel has been
floating around for a while. After talking with Dave Sterba, Herbert
and Phillip, we decided to send the whole thing in as one pull
request.
zstd is a big win in speed over zlib and in compression ratio over
lzo, and the compression team here at FB has gotten great results
using it in production. Nick will continue to update the kernel side
with new improvements from the open source zstd userland code.
Nick has a number of benchmarks for the main zstd code in his lib/zstd
commit:
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. I benchmarked using
`silesia.tar` [3], which is 211,988,480 B large. Run the following
commands for the benchmark:
sudo modprobe zstd_compress_test
sudo mknod zstd_compress_test c 245 0
sudo cp silesia.tar zstd_compress_test
The time is reported by the time of the userland `cp`.
The MB/s is computed with
1,536,217,008 B / time(buffer size, hash)
which includes the time to copy from userland.
The Adjusted MB/s is computed with
1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).
The memory reported is the amount of memory the compressor
requests.
| Method | Size (B) | Time (s) | Ratio | MB/s | Adj MB/s | Mem (MB) |
|----------|----------|----------|-------|---------|----------|----------|
| none | 11988480 | 0.100 | 1 | 2119.88 | - | - |
| zstd -1 | 73645762 | 1.044 | 2.878 | 203.05 | 224.56 | 1.23 |
| zstd -3 | 66988878 | 1.761 | 3.165 | 120.38 | 127.63 | 2.47 |
| zstd -5 | 65001259 | 2.563 | 3.261 | 82.71 | 86.07 | 2.86 |
| zstd -10 | 60165346 | 13.242 | 3.523 | 16.01 | 16.13 | 13.22 |
| zstd -15 | 58009756 | 47.601 | 3.654 | 4.45 | 4.46 | 21.61 |
| zstd -19 | 54014593 | 102.835 | 3.925 | 2.06 | 2.06 | 60.15 |
| zlib -1 | 77260026 | 2.895 | 2.744 | 73.23 | 75.85 | 0.27 |
| zlib -3 | 72972206 | 4.116 | 2.905 | 51.50 | 52.79 | 0.27 |
| zlib -6 | 68190360 | 9.633 | 3.109 | 22.01 | 22.24 | 0.27 |
| zlib -9 | 67613382 | 22.554 | 3.135 | 9.40 | 9.44 | 0.27 |
I benchmarked zstd decompression using the same method on the same
machine. The benchmark file is located in the upstream zstd repo
under `contrib/linux-kernel/zstd_decompress_test.c` [4]. The
memory reported is the amount of memory required to decompress
data compressed with the given compression level. If you know the
maximum size of your input, you can reduce the memory usage of
decompression irrespective of the compression level.
| Method | Time (s) | MB/s | Adjusted MB/s | Memory (MB) |
|----------|----------|---------|---------------|-------------|
| none | 0.025 | 8479.54 | - | - |
| zstd -1 | 0.358 | 592.15 | 636.60 | 0.84 |
| zstd -3 | 0.396 | 535.32 | 571.40 | 1.46 |
| zstd -5 | 0.396 | 535.32 | 571.40 | 1.46 |
| zstd -10 | 0.374 | 566.81 | 607.42 | 2.51 |
| zstd -15 | 0.379 | 559.34 | 598.84 | 4.61 |
| zstd -19 | 0.412 | 514.54 | 547.77 | 8.80 |
| zlib -1 | 0.940 | 225.52 | 231.68 | 0.04 |
| zlib -3 | 0.883 | 240.08 | 247.07 | 0.04 |
| zlib -6 | 0.844 | 251.17 | 258.84 | 0.04 |
| zlib -9 | 0.837 | 253.27 | 287.64 | 0.04 |
I ran a long series of tests and benchmarks on the btrfs side and the
gains are very similar to the core benchmarks Nick ran"
* 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
squashfs: Add zstd support
btrfs: Add zstd support
lib: Add zstd modules
lib: Add xxhash module
136 lines
4.1 KiB
C
136 lines
4.1 KiB
C
/*
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* Copyright (C) 2008 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __BTRFS_COMPRESSION_
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#define __BTRFS_COMPRESSION_
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/*
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* We want to make sure that amount of RAM required to uncompress an extent is
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* reasonable, so we limit the total size in ram of a compressed extent to
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* 128k. This is a crucial number because it also controls how easily we can
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* spread reads across cpus for decompression.
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*
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* We also want to make sure the amount of IO required to do a random read is
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* reasonably small, so we limit the size of a compressed extent to 128k.
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*/
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/* Maximum length of compressed data stored on disk */
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#define BTRFS_MAX_COMPRESSED (SZ_128K)
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/* Maximum size of data before compression */
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#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
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struct compressed_bio {
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/* number of bios pending for this compressed extent */
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refcount_t pending_bios;
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/* the pages with the compressed data on them */
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struct page **compressed_pages;
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/* inode that owns this data */
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struct inode *inode;
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/* starting offset in the inode for our pages */
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u64 start;
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/* number of bytes in the inode we're working on */
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unsigned long len;
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/* number of bytes on disk */
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unsigned long compressed_len;
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/* the compression algorithm for this bio */
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int compress_type;
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/* number of compressed pages in the array */
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unsigned long nr_pages;
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/* IO errors */
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int errors;
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int mirror_num;
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/* for reads, this is the bio we are copying the data into */
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struct bio *orig_bio;
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/*
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* the start of a variable length array of checksums only
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* used by reads
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*/
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u32 sums;
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};
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void btrfs_init_compress(void);
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void btrfs_exit_compress(void);
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int btrfs_compress_pages(int type, struct address_space *mapping,
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u64 start, struct page **pages,
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unsigned long *out_pages,
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unsigned long *total_in,
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unsigned long *total_out);
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int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
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unsigned long start_byte, size_t srclen, size_t destlen);
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int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
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unsigned long total_out, u64 disk_start,
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struct bio *bio);
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blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
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unsigned long len, u64 disk_start,
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unsigned long compressed_len,
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struct page **compressed_pages,
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unsigned long nr_pages);
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blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
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int mirror_num, unsigned long bio_flags);
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enum btrfs_compression_type {
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BTRFS_COMPRESS_NONE = 0,
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BTRFS_COMPRESS_ZLIB = 1,
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BTRFS_COMPRESS_LZO = 2,
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BTRFS_COMPRESS_ZSTD = 3,
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BTRFS_COMPRESS_TYPES = 3,
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};
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struct btrfs_compress_op {
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struct list_head *(*alloc_workspace)(void);
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void (*free_workspace)(struct list_head *workspace);
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int (*compress_pages)(struct list_head *workspace,
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struct address_space *mapping,
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u64 start,
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struct page **pages,
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unsigned long *out_pages,
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unsigned long *total_in,
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unsigned long *total_out);
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int (*decompress_bio)(struct list_head *workspace,
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struct compressed_bio *cb);
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int (*decompress)(struct list_head *workspace,
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unsigned char *data_in,
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struct page *dest_page,
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unsigned long start_byte,
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size_t srclen, size_t destlen);
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};
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extern const struct btrfs_compress_op btrfs_zlib_compress;
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extern const struct btrfs_compress_op btrfs_lzo_compress;
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extern const struct btrfs_compress_op btrfs_zstd_compress;
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int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
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#endif
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