ping ping On 04.03.2019 18:10, Denis Plotnikov wrote: > ping! > > On 26.02.2019 16:15, Denis Plotnikov wrote: >> zstd date compression algorithm shows better performance on data compression. >> It might be useful to employ the algorithm in VM migration to reduce CPU >> usage. >> A user will be able to choose between those algorithms, therefor >> compress-type >> migration parameter is added. >> >> Here are some results of performance comparison zstd vs gzip: >> >> host: i7-4790 8xCPU @ 3.60GHz, 16G RAM >> migration to the same host >> VM: 2xVCPU, 8G RAM total >> 5G RAM used, memory populated with postgreqsl data >> produced by pgbench performance benchmark >> >> >> Threads: 1 compress – 1 decompress >> >> zstd provides slightly less compression ratio with almost the same >> CPU usage but copes with RAM compression roghly 2 times faster >> >> compression type zlib | zstd >> --------------------------------------------------------- >> compression level 1 5 | 1 5 >> compression ratio 6.92 7.05 | 6.69 6.89 >> cpu idle, % 82 83 | 86 80 >> time, sec 49 71 | 26 31 >> time diff to zlib, sec -25 -41 >> >> >> Threads: 8 compress – 2 decompress >> >> zstd provides the same migration time with less cpu consumption >> >> compression type none | gzip(zlib) | zstd >> ------------------------------------------------------------------------------ >> compression level - | 1 5 9 | 1 5 15 >> compression ratio - | 6.94 6.99 7.14 | 6.64 6.89 >> 6.93 >> time, sec 154 | 22 23 27 | 23 23 25 >> cpu idle, % 99 | 45 30 12 | 70 52 23 >> cpu idle diff to zlib | | -25% -22% -11% >> >> >> Denis Plotnikov (3): >> migration: rework compression code for adding more data compressors >> hmp: add compress-type parameter to migration parameters >> migration: add zstd compression >> >> configure | 26 ++++ >> hmp.c | 8 ++ >> migration/migration.c | 45 ++++++- >> migration/migration.h | 1 + >> migration/qemu-file.c | 39 ++---- >> migration/qemu-file.h | 18 ++- >> migration/ram.c | 291 ++++++++++++++++++++++++++++++++++-------- >> qapi/migration.json | 26 +++- >> 8 files changed, 369 insertions(+), 85 deletions(-) >> >
-- Best, Denis