Re: building netbsd-9 2 'sync' processes stuck in 'tstile'

["John D. Baker" <jdbaker%consolidated.net@localhost>]

On Fri, 7 May 2021, Greg A. Woods wrote:

> I wonder if you could use crash(8) (or ddb(4)) to get kernel stack
> traces of the stuck processes.  (E.g. see the EXAMPLES section in
> crash(8).)
> 
> That might help narrow down which locks are causing the problems...

$ sudo sh -c "echo ps | crash | grep sync | cut -c 30-46 | sed 's,^,bt/a ,' | crash"

Crash version 9.1_STABLE, image version 9.1_STABLE.
Output from a running system is unreliable.
trace: pid 2923 lid 1 at 0xffff810060d26e80
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
mutex_vector_enter() at mutex_vector_enter+0x2b4
do_sys_sync() at do_sys_sync+0x45
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
75959464276a:
trace: pid 5301 lid 1 at 0xffff81007386ee80
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
mutex_vector_enter() at mutex_vector_enter+0x2b4
do_sys_sync() at do_sys_sync+0x45
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
707b67a4276a:
trace: pid 22487 lid 1 at 0xffff810073886e80
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
mutex_vector_enter() at mutex_vector_enter+0x2b4
do_sys_sync() at do_sys_sync+0x45
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
7a2641a4276a:
trace: pid 23870 lid 1 at 0xffff81006038ae80
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
mutex_vector_enter() at mutex_vector_enter+0x2b4
do_sys_sync() at do_sys_sync+0x45
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
7c73c264276a:
trace: pid 21539 lid 1 at 0xffff81005f4fee80
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
mutex_vector_enter() at mutex_vector_enter+0x2b4
do_sys_sync() at do_sys_sync+0x45
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
72a226c4276a:
trace: pid 22210 lid 1 at 0xffff81006078ed20
sleepq_block() at sleepq_block+0x19a
turnstile_block() at turnstile_block+0x2de
rw_vector_enter() at rw_vector_enter+0x11b
genfs_lock() at genfs_lock+0x40
VOP_LOCK() at VOP_LOCK+0x8b
vn_lock() at vn_lock+0x11
ffs_sync() at ffs_sync+0x98
VFS_SYNC() at VFS_SYNC+0x35
do_sys_sync() at do_sys_sync+0x6c
sys_sync() at sys_sync+0x9
syscall() at syscall+0x157
--- syscall (number 36) ---
78391de4276a:
trace: pid 0 lid 67 at 0xffff81005f300f40
sleepq_block() at sleepq_block+0xbb
kpause() at kpause+0x10b
sched_sync() at sched_sync+0x1e8

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