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(-) -- 2.17.0
