When you pin a tab, you no longer see the numbered update counts (right) for things such as Gmail, Twitter, and other services that give you a live count on the browser bar of new things going on within the page since the last time you were active on that tab.
How to make chrome pin tab and display title too?
Close some tabs or uninstall extensions that take a lot of memory. If there's a specific tab you don't want discarded, right-click on the tab and pin it.
I found this not work. When the memory is too low, it will reload, either. In the
chrome://discards/,the pin tab is also on top which means it is most closet to be discarded! Why?