How to resume OS X apps that have been suspended by the system

I often run into the situation where the OS will suspend some of my apps because of low memory. If I am lucky, a window will appear that allows me to select which apps I want to quit and which apps I want to resume, which works reliably and is fine. However, often that window does not appear. This is usually the case when my machine (mid-2015 MBP 15", 16GB RAM, OS X 10.11.2) has just woken from sleep. In that case, the only symptom is that I have a bunch of unresponsive apps that show as (Not responding) in Activity Monitor.

I have tried to resume processes by sending the CONT signal (either via Activity Monitor or via the Terminal) and for a small number of apps this works, but for the majority of apps it does not. For example, when this happened to me just now, I force quitted Preview (which was the chief memory hog) and tried to resume the other apps with CONT. This worked fine for Clear, but not for anything else. In some cases, such as Emacs, it had no effect - process still shows as (Not responding). In other cases, such as Bibdesk, it leaves the app in a strange unusable state where the main window refuses to appear on screen and the menus don't work.

So how can I force that process management window to appear, or otherwise do whatever magic it is doing to "resume" apps?

More googling revealed that the process management window I am looking for is the "Force Quit Applications" dialog, and that it can be easily accessed from the Apple () menu or with the keyboard shortcut Command Option Escape. In normal use, this only has a Force Quit button, but it should also have a Resume button if the system suspends any of my processes again (although I can't directly test this at the moment).

I encountered this same issue. THe CONT signal did not work and there was no Resume button on the Force Quit dialog. I did not want to force quit the app, because I would lose my work. Here is what worked for me:

I sent a STOP signal through Activity Monitor and the app resumed, in this case word, and popped a dialog asking if I wanted to save my work. I selected cancel and began using the app as normal.