Hi Sasha, I got the below warning and it's bisected to commit 42f8570f437b65aaf3ef176a38ad7d7fc5847d8b Author: Sasha Levin Date: Mon Dec 17 10:01:23 2012 -0500 workqueue: use new hashtable implementation [ 89.243805] write_dev_root_ (3265) used greatest stack depth: 2704 bytes left [ 89.666207] ------------[ cut here ]------------ [ 89.667098] WARNING: at /c/kernel-tests/src/stable/block/genhd.c:1574 disk_clear_events+0xcf/0x108() [ 89.668040] Hardware name: Bochs [ 89.668040] Modules linked in: [ 89.668040] Pid: 3328, comm: ata_id Not tainted 3.7.0-01930-gbff6343 #1167 [ 89.668040] Call Trace: [ 89.668040] [] warn_slowpath_common+0x83/0x9c [ 89.671922] [] warn_slowpath_null+0x1a/0x1c [ 89.671922] [] disk_clear_events+0xcf/0x108 [ 89.671922] [] check_disk_change+0x27/0x59 [ 89.671922] [] cdrom_open+0x49/0x68b [ 89.671922] [] ? __mutex_unlock_slowpath+0x116/0x126 [ 89.671922] [] ? trace_hardirqs_on_caller+0x123/0x17f [ 89.671922] [] ? __mutex_unlock_slowpath+0x11e/0x126 [ 89.671922] [] idecd_open+0x88/0xb7 [ 89.671922] [] __blkdev_get+0x102/0x3ec [ 89.671922] [] blkdev_get+0x18f/0x30f [ 89.671922] [] ? lock_release+0x17d/0x1cd [ 89.671922] [] ? blkdev_get+0x30f/0x30f [ 89.671922] [] ? _raw_spin_unlock+0x28/0x3b [ 89.671922] [] ? blkdev_get+0x30f/0x30f [ 89.671922] [] blkdev_open+0x75/0x80 [ 89.671922] [] do_dentry_open+0x1ea/0x295 [ 89.671922] [] finish_open+0x35/0x41 [ 89.671922] [] do_last+0x878/0xa25 [ 89.671922] [] ? inode_permission+0x45/0x47 [ 89.671922] [] path_openat+0xc6/0x333 [ 89.671922] [] ? lock_release_holdtime.part.22+0x4e/0x55 [ 89.671922] [] do_filp_open+0x38/0x86 [ 89.671922] [] ? spin_unlock+0x9/0xb [ 89.671922] [] ? __alloc_fd+0xf3/0x104 [ 89.671922] [] do_sys_open+0x6c/0xf9 [ 89.671922] [] sys_open+0x21/0x23 [ 89.671922] [] system_call_fastpath+0x16/0x1b Thanks, Fengguang