GitLab

* Add diagnosis module for precise identification of slow ranks
Signed-off-by: wangfakang <fakangwang@gmail.com>

* Add tests for the slow diagnosis module
Signed-off-by: wangfakang <fakangwang@gmail.com>

* Update some comments for diagnose
Signed-off-by: wangfakang <fakangwang@gmail.com>

* Update test case for diagnose
Signed-off-by: wangfakang <fakangwang@gmail.com>

* Strip the diagnose module, thx LyricZhao and sphish.
Signed-off-by: wangfakang <fakangwang@gmail.com>

* update variable name and cumulative wait recv cost, thx sphish.
Signed-off-by: wangfakang <fakangwang@gmail.com>

* remove invalid comments.
Signed-off-by: wangfakang <fakangwang@gmail.com>

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Signed-off-by: wangfakang <fakangwang@gmail.com>