Michal Hocko wrote: > > Strictly speaking, neither debug_show_all_locks() nor debug_show_held_locks() > > are safe enough to guarantee that the system won't crash. > > > > commit 856848737bd944c1 "lockdep: fix debug_show_all_locks()" > > commit 82a1fcb90287052a "softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks" > > > > They are convenient but we should avoid using them if we care about > > possibility of crash. > > I really fail to see your point. debug_show_all_locks doesn't mention > any restriction of the risk nor it is restricted to a particular > context. Were there some bugs in that area? Probably yes, so what? commit 856848737bd944c1 changed that locks held by TASK_RUNNING tasks are not reported. We might fail to report the task which is holding mmap_sem for write when we call debug_show_all_locks() in order to find such task. Therefore, I think guessing from sched_show_task() output can be used. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>