We all have things we check when reviewing patches. Some of us have spent a lot of time fixing locking problems, so we pay close attention to any locking. Some of us have spent a lot of time dealing with error handling, so we closely pay attention to error handling. Everybody has different experiences which makes them look at different things. This is why patch review is so important, the person writing the code and the person reviewing the code have different viewpoints and different things they look for, so together we can come up with better code.

That being said it’s helpful to have a process, so you are an effective and helpful patch reviewer. Patch reviews will not catch all problems, but maintainers should trust that you are doing a thorough job. This isn’t meant to be an exhaustive list of what you should do, but these are fundamental things that can be done to help make sure we’re applying quality code.