Git : changes to my local repository but not pushed upstream

This is a git question.

I have a private github repository for an application.

After a couple of hours of work and a few commits I want to know what
all commits have not been pushed to the github server.

When I execute git cherry -v origin I get following error.
fatal: Unknown commit origin

However when I execute git push origin all the pending commits gets
pushed.

Anyone knows how to get the list of commits which are local but not
pushed upstream.