Re: [Qemu-devel] [PATCH 0/3] migration: add sztd compression

[Denis Plotnikov]

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