+++ This bug was initially created as a clone of Bug #670596 +++ Currently there is no way in about:memory to trigger the shrinking GC that releases all empty GC chunks and decommits unused GC arenas. It would be nice if the "Minimize memory usage" button or even the "GC" button should run a shrinking GC.
(In reply to Justin Lebar [:jlebar] from comment #1) > > *** This bug has been marked as a duplicate of bug 699279 *** I though bug 699279 was about doing the shrinking GC under memory pressure. This is unrelated to about:memory GUI.
When you click minimize memory usage in about:memory, it does a memory pressure event.