The particular issue of locking up a system because there are too many tabs open in Firefox or Chrome should be fixed in the browser, because the browser is the

The particular issue of locking up a system because there are too many tabs open in Firefox or Chrome should be fixed in the browser, because the browser is the program that is taking up all of the memory and is in the best position to know how to recover a lot of memory quickly while minimizing the loss of work for the user. One of the comments suggested having the kernel send a 'memory pressure' signal to all processes, and a process could catch the signal and do garbage collection or drop other storage. But even without such a feature, a program could do polling to determine that there is memory pressure, or do a check when a user asks to open a new tab, etc.