| Message ID | 20230526210201.12661-1-dsterba@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: add xxhash to fast checksum implementations | expand |
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 107291c291d2..1a250291832d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2014,6 +2014,9 @@ 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; }
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MiB/s XXHASH: cycles: 860656400, cycles/i 860, 16338.188 MiB/s Comparing purely software implementation (ref), current outdated accelerated using crc32q instruction (NI), optimized implementations by M. Adler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). Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/disk-io.c | 3 +++ 1 file changed, 3 insertions(+)