Hello, > i wrote a linux kernel module which uses mmap_sem in lots of places. I grab > mmap_sem for both reads & writes. And, i also use page_table_lock spinlock > under them. The problem i have is that there is a hard to reproduce a race > condition bug in which a thread doesn't release the semaphore at all. Hence, > ps hangs as ps needs to grab mmap_sem for the processes. The question is how > do i find the thread that is holding the semaphore forever. It will help me > figure out the part of the code the race is in. > So, the question is : I have some number of threads grabbing the semaphore > for read/write. One of them grabs it & doesn't release at all. How do i find > the thread that is holding it. This is not a soft lockup & i dont get any > hung_task_timeout messages. > Any help is appreciated. You could turn on lockdep (LOCKDEP_SUPPORT=y), and see if any warnings are triggered. thanks, Daniel. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
