[DragonFlyBSD - Bug #2994] Intermittent boot hangs after git: hammer - HAMMER Version 7

bugtracker-admin at leaf.dragonflybsd.org bugtracker-admin at leaf.dragonflybsd.org
Tue Mar 28 12:52:42 PDT 2017

Issue #2994 has been updated by dillon.

Did it get to the 'CAM: Configuring N busses' and 'CAM: finished configuring all busses' before hanging?  If not then it will stop there waiting for CAM to finish configuring.

There is a possible deadlock somewhere in CAM from changes made in Feb to fix some other holes in CAM's locking.  The fact that a verbose boot worked makes that all the more likely to be the issue.  Kind of a chicken and egg issue.   What I really need is a backtrace of the offending kernel threads but that might be difficult at that point in the boot.  you might be able to ctl-alt-esc into the debugger, but it would take some messing around to get a decent trace of the offending threads (basically you have to find the stack addresses which is typically listed in the thread list and x/a <addr> then hit return a ton of times to dump the stack for each thread).  I don't know if the symbol table will be available at that point in the boot sequence.


Bug #2994: Intermittent boot hangs after git: hammer - HAMMER Version 7

* Author: davshao
* Status: New
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
Bisected to git: hammer - HAMMER Version 7
commit 4c09d9c4fd910651904ede280ad90a4abf3fc5d7
Date:   Fri Mar 17 14:06:24 2017 -0700

    hammer - HAMMER Version 7

intermittent boot hangs stopping at

ums0: <Logitech USB-PS2 Optical Mouse, class 0/0, rev 2.00/20.00, addr 5> on usb
ums0: 3 buttons and [XYX] coordinates ID=0
no B_DEVMAGIC (bootdev=0)

Boot proceeds normally when using verbose option which is why I can attach
the verbose dmesg.

The machine uses a refurbished Asus P8H77-V motherboard with several
internal hard drives with different OSes using legacy BIOS.

$ hammer info
Volume identification
	Label               ROOT
	No. Volumes         1
	HAMMER Volumes      /dev/serno/WD-WMAYP5624974.s3d
	Root Volume         /dev/serno/WD-WMAYP5624974.s3d
	FSID                9d8141cd-c974-11e5-9ccd-bd5ff4499104
	HAMMER Version      6
Big-block information
	Total           29669
	Used             9119 (30.74%)
	Reserved           70 (0.24%)
	Free            20480 (69.03%)
Space information
	No. Inodes     856028
	Total size       232G (248881610752 bytes)
	Used              71G (30.74%)
	Reserved         560M (0.24%)
	Free             160G (69.03%)
PFS information
	  PFS#  Mode    Snaps
	     0  MASTER      0 (root PFS)

p8h77v_dmesg.txt (63.3 KB)

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