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