对比v2.3.20，v2.4.x创建IVF_PQ索引性能相差~60倍

[xsmq]

1、create_index参数
index_type: IVF_PQ
nlist: 128
m: 120
metric: L2

2、数据集
gist：100万条数据

3、cluster集群
node：3 * 16C64G
indexnode pod：3

4、性能对比
v2.3.20：创建索引时间 ~589s
v2.4.6：创建索引时间 ~35856s（v2.4.1和v2.4.5跑出来的结果同样很差）
性能劣化近60倍

[cydrain]

Milvus	Knowhere	Cardinal
v2.3.20	v2.2.7	2.2.10
v2.4.6	v2.3.5-hotfix	v2.4.5-hotfix

[cydrain]

File a issue zilliztech/knowhere#739 to track this

[alexanderguzhva]

The correct solution is not to install libopenblas, but to install libopenblas0-openmp instead (or libopenblas-openmp-dev) for Ubuntu.

[liliu-z]

Solved by zilliztech/knowhere#741
Will release this with Milvus 2.4.7

[xsmq]

it's great!!!