Setting a barrier point at the current PC for a stopped process or thread holds the process there. If, however, all other processes or threads affected by the barrier point are at the same PC, TotalView doesn’t hold them. Instead, TotalView treats the barrier point as if it were an ordinary breakpoint.

TotalView releases all processes and threads that are held and which have threads at the barrier point when you disable the barrier point (by right-clicking on it in the Action Points tab and selecting Disable).