Please trim.. On Fri, Feb 16, 2018 at 12:02:42AM +0000, Mathieu Desnoyers wrote: > > My current theory: do_exit() gets preempted after having set current->mm > > to NULL, and after having issued mmput(), which brings the mm_count down > > to 0.
No it doesn't.. remember, the last thread of a process enters with: mm_count == 1 && mm_users == 1 exit_mm() then does mmgrab(): mm_count == 2 && mm_users == 1 we then do mmput(), which results in: mm_count == 1 && mm_users == 0 That last mm_count is for ->active_mm, and will be dropped once we schedule to a next user task.
