I hit a following problem when run a oom case in ltp. The kernel version is 4.1 stable. [ 601.937145] Call trace: [ 601.939600] [<ffffffc000086a88>] __switch_to+0x74/0x8c [ 601.944760] [<ffffffc000a1bae0>] __schedule+0x23c/0x7bc [ 601.950007] [<ffffffc000a1c09c>] schedule+0x3c/0x94 [ 601.954907] [<ffffffc000a1eb84>] rwsem_down_write_failed+0x214/0x350 [ 601.961289] [<ffffffc000a1e32c>] down_write+0x64/0x80 [ 601.966363] [<ffffffc00021f794>] __ksm_exit+0x90/0x19c [ 601.971523] [<ffffffc0000be650>] mmput+0x118/0x11c [ 601.976335] [<ffffffc0000c3ec4>] do_exit+0x2dc/0xa74 [ 601.981321] [<ffffffc0000c46f8>] do_group_exit+0x4c/0xe4 [ 601.986656] [<ffffffc0000d0f34>] get_signal+0x444/0x5e0 [ 601.991904] [<ffffffc000089fcc>] do_signal+0x1d8/0x450 [ 601.997065] [<ffffffc00008a35c>] do_notify_resume+0x70/0x78 ksm_exit should take the write lock and wait all read lock is released. in fact, but I find ksmd still hold a read lock in scan_get_next_rmap_item. thefefore, it will lead to hungtask. Any suggestion will be appreciated. Thanks zhongjiang -- 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>