Why my plugin is so time consuming?

My plugin is to add a web-panel at atl.jira.view.issue.left.context. It looks great in local env. When i do Performance and scale testing, the result shows it is time consuming. I do not see any error logs. Could anyone please tell me why or how to solve it? Thanks

With out the content of the plugin there is no evidence of why.
What is in the panel?