Hello Chen, On Sun, Oct 04, 2015 at 12:55:29PM +0800, Chen Gang wrote: > Theoretically, the lock and unlock need to be symmetric, if we have to > lock f_mapping all firstly, then lock all anon_vma, probably, we also > need to unlock anon_vma all, then unlock all f_mapping. They don't need to be symmetric because the unlocking order doesn't matter. To avoid lock inversion deadlocks it is enough to enforce the lock order. -- 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>