==> /proc/5326/task/5326/stack <== [] ep_poll+0x153/0x240 [] sys_epoll_wait+0xd4/0xe0 [] system_call_fastpath+0x16/0x1b [<00007f1c9b390ed3>] 0x7f1c9b390ed3 [] 0xffffffffffffffff ==> /proc/5326/task/5328/stack <== [] sys_rt_sigtimedwait+0x23a/0x290 [] system_call_fastpath+0x16/0x1b [<00007f1c9b9a42a7>] 0x7f1c9b9a42a7 [] 0xffffffffffffffff ==> /proc/5326/task/5329/stack <== [] futex_wait_queue_me+0xb5/0x100 [] futex_wait+0x146/0x2e0 [] do_futex+0xc5/0x1b0 [] sys_futex+0x82/0x160 [] system_call_fastpath+0x16/0x1b [<00007f1c9b9a042c>] 0x7f1c9b9a042c [] 0xffffffffffffffff ==> /proc/5326/task/5330/stack <== [] futex_wait_queue_me+0xb5/0x100 [] futex_wait+0x146/0x2e0 [] do_futex+0xc5/0x1b0 [] sys_futex+0x82/0x160 [] system_call_fastpath+0x16/0x1b [<00007f1c9b9a042c>] 0x7f1c9b9a042c [] 0xffffffffffffffff ==> /proc/5326/task/5332/stack <== [] hrtimer_nanosleep+0xa8/0x140 [] sys_nanosleep+0x70/0x80 [] system_call_fastpath+0x16/0x1b [<00007f1c9b9a3dbd>] 0x7f1c9b9a3dbd [] 0xffffffffffffffff ==> /proc/5326/task/5351/stack <== [] call_rwsem_down_read_failed+0x14/0x30 [] 0xffffffffffffffff ==> /proc/5326/task/5352/stack <== [] pipe_wait+0x52/0x70 [] pipe_read+0x3d3/0x4a0 [] do_sync_read+0xe3/0x130 [] vfs_read+0xc7/0x130 [] sys_read+0x53/0xa0 [] system_call_fastpath+0x16/0x1b [<00007f1c9b9a357d>] 0x7f1c9b9a357d [] 0xffffffffffffffff