Closed marcin-github closed 11 months ago
I compiled crc32c_intel
and crc32_pclmul
into kernel and now I can;t see crc32_body in perf. I see crc_128 but it is very low on perf, crc_128 lloks for me that is from crc32c-pcl-intel-asm
# echo 3 > /proc/sys/vm/drop_caches ; sleep 1 ; time dd if=2021-11-26-1637885176-fdns_any.json.zst of=/dev/null bs=128k
356068+1 przeczytanych rekordów
356068+1 zapisanych rekordów
skopiowane 46670624913 bajtów (47 GB, 43 GiB), 181,14 s, 258 MB/s
real 3m1,145s
user 0m1,287s
sys 1m23,870s
bcachefs doesnt support crypto engine yet, as such all checksums are done in software. This will be a nice enchantement, once it becomes stable enough to handle async crypto
It looks that computating crc while reading uses only software crc function. I create two big files, one was written with crc selected as data_checksum, second was created with xxhash. Fs is on ssd drive. Benchmarks and output from
perf top
:for file with crc checksum
perf:
and for xxhash:
CPU is
i5-6500T
list of loaded modules: