using `sync.Pool` to reuse `Job`

[kemingy]

• benchmark
• sync.Pool

Ref

• https://www.cockroachlabs.com/blog/how-to-optimize-garbage-collection-in-go/

[kemingy]

data and result can be one object.

sync.Pool doesn't help you clean the old data.

[kemingy]

It seems this is not the bottleneck for deep learning model serving. Because it won't have too many requests like CRUD services.

[kemingy]

It seems this is not the bottleneck for deep learning model serving. Because it won't have too many requests like CRUD services.

This should be able to reduce the GC. Need to run for a long time to see the difference.