Hello, On (06/02/16 11:21), Michal Hocko wrote: [..] > @@ -2863,6 +2854,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, > > collect_mm_slot(mm_slot); > } > + mmput(mm); > > return progress; > } this possibly sleeping mmput() is called from under the spin_lock(&khugepaged_mm_lock). there is also a trivial build fixup needed (move collect_mm_slot() before __khugepaged_exit()). it's quite hard to trigger the bug (somehow), so I can't follow up with more information as of now. -ss -- 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>