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authorDavid Sterba <dsterba@suse.com>2023-04-04 01:06:02 +0300
committerDavid Sterba <dsterba@suse.com>2023-06-19 14:59:33 +0300
commitefcfcbc6a36195c42d98e0ee697baba36da94dc8 (patch)
treede0af3cb3a2a377d38d9997571449c95cc4a7b3c /fs/btrfs/disk-io.c
parentf000bc6fe43ce66c55fa1691000115b14ba95b33 (diff)
downloadlinux-efcfcbc6a36195c42d98e0ee697baba36da94dc8.tar.xz
btrfs: add xxhash to fast checksum implementations
The implementation of XXHASH is now CPU only but still fast enough to be considered for the synchronous checksumming, like non-generic crc32c. A userspace benchmark comparing it to various implementations (patched hash-speedtest from btrfs-progs): Block size: 4096 Iterations: 1000000 Implementation: builtin Units: CPU cycles NULL-NOP: cycles: 73384294, cycles/i 73 NULL-MEMCPY: cycles: 228033868, cycles/i 228, 61664.320 MiB/s CRC32C-ref: cycles: 24758559416, cycles/i 24758, 567.950 MiB/s CRC32C-NI: cycles: 1194350470, cycles/i 1194, 11773.433 MiB/s CRC32C-ADLERSW: cycles: 6150186216, cycles/i 6150, 2286.372 MiB/s CRC32C-ADLERHW: cycles: 626979180, cycles/i 626, 22427.453 MiB/s CRC32C-PCL: cycles: 466746732, cycles/i 466, 30126.699 MiB/s XXHASH: cycles: 860656400, cycles/i 860, 16338.188 MiB/s Comparing purely software implementation (ref), current outdated accelerated using crc32q instruction (NI), optimized implementations by M. Adler (https://stackoverflow.com/questions/17645167/implementing-sse-4-2s-crc32c-in-software/17646775#17646775) and the best one that was taken from kernel using the PCLMULQDQ instruction (PCL). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
-rw-r--r--fs/btrfs/disk-io.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4328c6b1120e..7513388b0567 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2011,6 +2011,9 @@ static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
if (!strstr(crypto_shash_driver_name(csum_shash), "generic"))
set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
break;
+ case BTRFS_CSUM_TYPE_XXHASH:
+ set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
+ break;
default:
break;
}