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

[Denis Plotnikov]

ping ping ping ping!

On 11.03.2019 11:20, Denis Plotnikov wrote:
> ping 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