sts validation on project builders have a high cpu

spring tool suite version 3.6.4 on my mac os. when I choose the validation on project builders ![enter image description here][1]

[1]: http://ift.tt/1G00WGm like this, the cpu is very high,when I I not choose the validation,the cpu is very lower,so I think this is maybe a problem ，I want to kown how to solve the problem，think you very much.