> > It always seems to freeze at DM_DEV_SUSPEND. This ioctl never > > seems to return. > > As with any other kernel frozen task - try to capture kernel stack > trace. If you properly configured sysrq trigger - easiest is to use: > > 'echo t >/proc/sysrq-trigger' > > (Just make sure you have large enough kernel log buffer so lines are > not lost) Attach compressed trace - this should likely reveal where > it blocks. (I'll try to reproduce myself) Thanks for the advice. I'm getting a warning that the buffer is overflowing. Is there anything in particular you need? Here is something that seems relevant: dmsetup D ffff880394467b98 0 24732 24717 0x00000000 ffff880394467b98 ffff88040d7a1e90 ffff88027b738a30 ffff88040ba67458 ffff880394468000 ffff8801eaa7b8dc ffff88027b738a30 00000000ffffffff ffff8801eaa7b8e0 ffff880394467bb8 ffffffff81588247 ffff8801eaa7b8d8 Call Trace: [<ffffffff81588247>] schedule+0x37/0x90 [<ffffffff81588615>] schedule_preempt_disabled+0x15/0x20 [<ffffffff81589b55>] __mutex_lock_slowpath+0xd5/0x150 [<ffffffff81589beb>] mutex_lock+0x1b/0x30 [<ffffffffa0857968>] dm_suspend+0x38/0xf0 [dm_mod] [<ffffffffa085d030>] ? table_load+0x370/0x370 [dm_mod] [<ffffffffa085d1c0>] dev_suspend+0x190/0x260 [dm_mod] [<ffffffffa085d030>] ? table_load+0x370/0x370 [dm_mod] [<ffffffffa085da72>] ctl_ioctl+0x232/0x520 [dm_mod] [<ffffffffa085dd73>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [<ffffffff811f4606>] do_vfs_ioctl+0x2c6/0x4d0 [<ffffffff811f4891>] SyS_ioctl+0x81/0xa0 [<ffffffff8158beae>] system_call_fastpath+0x12/0x71 Assuming 24732 is the PID, that's the "dmsetup suspend --noflush --nolockfs" one. There are heaps like the one above (from all my attempts) with only one like the following, from an unknown command line: dmsetup D ffff88012e2d7a88 0 28744 23911 0x00000004 ffff88012e2d7a88 ffff88040d74f010 ffff88040398e5e0 ffff88012e2d7b38 ffff88012e2d8000 ffff8800d9df5080 ffff8800d9df5068 ffffffff00000000 fffffffe00000001 ffff88012e2d7aa8 ffffffff81588247 0000000000000002 Call Trace: [<ffffffff81588247>] schedule+0x37/0x90 [<ffffffff8158a885>] rwsem_down_write_failed+0x165/0x370 [<ffffffff810b2ad6>] ? enqueue_entity+0x266/0xd60 [<ffffffff812d7aa3>] call_rwsem_down_write_failed+0x13/0x20 [<ffffffff8158a0d4>] ? down_write+0x24/0x40 [<ffffffff811e3aee>] grab_super+0x2e/0xb0 [<ffffffff811e4a20>] get_active_super+0x70/0x90 [<ffffffff8121ab9d>] freeze_bdev+0x6d/0x100 [<ffffffffa0854f3b>] __dm_suspend+0xeb/0x230 [dm_mod] [<ffffffffa08579fa>] dm_suspend+0xca/0xf0 [dm_mod] [<ffffffffa085d1db>] dev_suspend+0x1ab/0x260 [dm_mod] [<ffffffffa085d030>] ? table_load+0x370/0x370 [dm_mod] [<ffffffffa085da72>] ctl_ioctl+0x232/0x520 [dm_mod] [<ffffffffa085dd73>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [<ffffffff811f4606>] do_vfs_ioctl+0x2c6/0x4d0 [<ffffffff811f4891>] SyS_ioctl+0x81/0xa0 [<ffffffff8158beae>] system_call_fastpath+0x12/0x71 The kernel is Arch Linux 4.1.4-1-ARCH. Let me know if you need anything else, sorry I don't have much experience with kernel debugging. Not sure whether /proc/kcore etc. is useful or not. Thanks again for your help! Cheers, Adam. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
