On 2019-01-30 18:56:54 [+0100], Thomas Gleixner wrote: > TBH, no clue. Below are some more traceprintks which hopefully shed some > light on that mystery. See kernel/futex.c line 30 ... The robust list it somehow buggy. In the last trace we had the handle_futex_death() of uaddr 3ff9e880140 as the last action. That means it was an entry in 56496's ->list_op_pending entry. This makes sense because it tried to acquire the lock, failed, got killed. According to uaddr pid 56956 is the owner. So 56956 invoked one of pthread_mutex_lock() / pthread_mutex_timedlock() / pthread_mutex_trylock() and should have obtained the lock in userland. Depending on where it got killed, that mutex should be either recorded in ->list_op_pending or the robust_list (or both if it didn't clear ->list_op_pending yet). But it is not. Similar for pthread_mutex_unlock(). We don't have a trace_point if we abort processing the list. On the other hand, it didn't trigger on x86 for hours. Could the atomic ops be the culprit? > Thanks, > > tglx Sebastian
