Hook rephist subsystem into the OOM handler
It appears we do not look at the
rephist subsystem in the OOM handler.
But, we do track memory allocation with
rephist_total_alloc counter. That counter needs to be audited because I found two places where we allocate memory for stats but do not increment that global counter.
Bug #25141 (moved) could have been avoided in some ways with this or at least made obvious to the operator without tor crashing.