Never had to do that but if you don't want to lock in the .log .
Maybe you can check if the .vmx file has changed but, this only will tell you if any config from the VM has changed.
Thanks for your reply , but i need to check whether number of cpu has been changed or not.
If it was a hot add, you should see something like 'Receiving Chipset.SetVCpuCount request' in the vmware.log. If the VM was down, the vmware.log does not update.
I found a post that could help you, if you implement it : https://www.virtuallyghetto.com/2015/08/how-to-audit-vm-reconfigurations-and-see-what-exactly-changed.html
But if you still don't have anything implemented I think that you can't do anything.