Michael Yao

@chenwhql @jiangjiajun @jczaja @wozna

@jiangjiajun can you help have a look at the CI coverage error of this PR?

updating on behalf of @piotrekobi - we found big accuracy drop for a model caused by this PR in our test... currently we are re-testing to ensure it is not...

请问部署的时候，Flags_use_mkldnn 是保持为0（缺省值）吗？

能试试=0的情况吗？

另外问个问题，use_mkldnn=1，但是pcrv3的话，速度也是正常的（1-2s）？ 换句话说PCRv4和v3的差别就能导致这个性能降级？